See the bottom of this page for a description of the icons on the page.

As of July 8, 2008, all exponents below 17,000,000 have been double-checked. As of July 4, 2008, all exponents below M(20996011) have been tested at least once.

Unix users can participate in GIMPS using precompiled clients or source code at Ernst Mayer's site and the manual testing forms at the PrimeNet server.

Clients can be downloaded from the project's download page. Version 24.14 of the prime95 client is available for Windows 95/98/Me/NT/2000/XP as of August 9, 2005. Version 24.14 or the mprime (or statically linked sprime) client is available for Linux and FreeBSD as of August 9, 2005. Clients are also available for Windows NT/2000/XP Service, OS/2, and Windows 3.1. See a complete list of features in these versions. See the download page for information about cliens for Apple/PowerPC, StrongARM, and UNIX machines.

See the project's wiki.

Join a discussion forum about this project.

GIMPS also has a sub-project: ECM and P-1 Factoring. This project is "trying to factor numbers of the form 2^N - 1 and 2^N + 1 using either the P - 1 method or the Elliptic Curve Method (ECM)." On September 13, 2004, this project "found a 53-digit factor for M971. This was the smallest Mersenne number for which no factors were known!"

The OGR-NG project is finding optimal rulers for 26, 27, 28, and higher marks. It began work on OGR-26 in October, 2008, and completed work on the project on February 23, 2009. It verified that the current best 26-mark ruler was optimal. It began work on OGR-27 on February 23, 2009. That project is still active.

See the project's download page for the latest version of the client, and the project's pre-release page for versions which are available for testing before they become official versions.

Use the RC5 key-rate calculator to see approximately what OGR node-rate your CPU will produce. The calculator was created by CalicoJak in January, 2003, and was last updated on February 22, 2006.

PS3

Submit new primes to the Top 5000 Primes list. Version 7.1 of Proth is available as of July 12, 2005.

As of January 19, 2010, the project has finished double-checking numbers for all k < 1,200 and n < 600,000. As of February 15, 2010, the project has extended its reservations to all k < 1,200 and n < 900,000.

To participate in the project, download the client (available for Windows, Linux, Solaris and various other flavors of Unix), download the Cunningham input list (see the link on the project website), then run the client and report any factors it finds through a link on the project website. Version 2.7.0 of the ECMNet client/server is available as of December 3, 2005.

On February 6, 2003, a project member discovered the largest (6,2,5) result above 60,000.

On December 8, 2002, a project member found a new upper limit for Taxicab(6): Taxicab(6) <= 24153319581254312065344, since 24153319581254312065344 = 28906206³ + 582162³ = 28894803³ + 3064173³ = 28657487³ + 8519281³ = 27093208³ + 16218068³ = 26590452³ + 17492496³ = 26224366³ + 18289922³. The Taxicab problem isn't a part of the Minimal Equal Sums of Like Powers project, but this is a big discovery nonetheless.

Version 4.21b of the client is available as of September 30, 2002. This version handles reserved work ranges better, points to the new eulernet.org domain automatically, and on the server side, allows for simultaneous client connections. Note: you should upgrade from version 4.18 and earlier to fix a significant client bug in those versions. Note: 4.21b has a bug which prevents the client from connecting to the server if you try to reserve more than the maximum 100 ranges. Use temporary version 4.21c to fix the bug.

Note: the project server was switched to a new ISP and domain, eulernet.org, as of October 15, 2002. The client should use eulernet.org when trying to connect to the project server. If your client can't connect to the project server, try pressing Ctrl-U, then changing the server name from eulernet.org to euler.myip.org. This may solve your problem if the DNS is incorrect.

Join a discussion forum about the project.

Note that the project website is not accessible as of October 29, 2009. If you know of a new URL for the project or if the project has ended, please let me know.

The project completed its first goal, processing 20,000 blocks, on November 19, 2002. The project found a new glide record in December, 2002. This is the first glide record found in almost a year. The record occurs at 180352,746940,718527, and the new glide is 1575, an improvement of 104 over the previous record. The project found a new Path record in March, 2003. The previous Path record was found in late 2002. The record occurs at 212581,558780,141311, (or +/- 189.2⁵⁰) and it reaches a maximum of 4353,436332,008631,522202,821543,171376. As of November 2, 2008, the project completed all blocks up to 67,500 and confirmed class record 2000.

See the project's progress.

This site is also available in Italian , Russian , and German .

Version 4.1 of the client is available as of September 7, 2001. Version 2.0 of the project's GMP_Fermat client is available as of June 10, 2008. Version 3.2.3 of the project's PFGW client is available as of November 3, 2009.

The project has found the following factors recently:

Factor	Discoverer	Date
1595863660157.287 + 1 divides F83	Vasily Danilov	May 12, 2005
2018719057.21162 + 1 divides F1160	Maximilian Pacher	May 15, 2005
351276975.21719 + 1 divides F1710	Maximilian Pacher	March 9, 2008
364182745.21724 + 1 divides F1722	Maximilian Pacher	April 19, 2008
6089.279223 + 1 divides F79221	Payam Samidoost	August 1, 2008
71007.249490 + 1 divides F49488	Takahiro Nohara	April 18, 2009
1814649.212827 + 1 divides F12825	Takahiro Nohara	October 9, 2009
84977118993.2520 + 1 divides F517	Sergei Maiorov	January 25, 2010
1784180997819127957596374417642156545110881094717.216 + 1 divides F14	Sergei Maiorov	February 3, 2010
81909357657279.254 + 1 divides F52	Cedric Vonck	March 15, 2010

To participate in the project, download a precompiled, statically linked executable for Linux ELF, FreeBSD ELF, Solaris 5.6, or Windows (you can also download and compile the source code), and also download a perl script called PcpSieve.pl which runs the executable, scans the output for record solutions, and emails the solutions to the project coordinator (you can also run the executable manually, search the output manually and email any record solutions you find). Note to Windows users: the Windows client was compiled by Michael Keppler of Rechenkraft.net. He says that it has a serious memory leak, and that you may need to kill it and restart it every day. If anyone knows how to debug Windows application memory leaks, please contact him.

This site is also available in German.

On January 6, 2003, Daniel Heuer discovered the largest known Generalized Fermat prime 1483076⁶⁵⁵³⁶+1 (404,434 digits), with GFNSieve+Proth, beating his previous record from October 8, 2002. "This number is the new largest known prime which is not a Mersenne prime, and the 6th largest known prime." On February 16, 2003, Michael Angel discovered the first prime of the form b²¹⁷ + 1: 62722¹³¹⁰⁷² + 1 (628,808 digits). This number is the 5th largest known prime. On February 21, 2003, the project completed the whole range 2-2,200,000 for exponent 32768. It found 35 primes in this range. On March 26, 2003, Franz Hagel discovered the 20th Generalized Fermat prime of the form b⁶⁵⁵³⁶ + 1: 357868⁶⁵⁵³⁶ + 1 (363,969 digits). On July 12, 2003, Michael Angel discovered the second known prime of the form b²¹⁷ + 1: 130816¹³¹⁰⁷² + 1. On August 22, 2003, Daniel Heuer discovered the largest known Generalized Fermat prime: 1176694²¹⁷ + 1. This 795,695 digit number is now the 5th largest known prime. On September 22, 2003, Daniel Heuer discovered the new largest known Generalized Fermat prime: 1372930²¹⁷ + 1. This 804,474 digit number is now the 5th largest known prime. On January 8, 2004, Yves Gallot discovered the 5th Generalized Fermat prime of the form b¹³¹⁰⁷² + 1: 572186²¹⁷ + 1 (754,652 digits). On May 30, 2004, Daniel Heuer discovered the two largest known Generalized Fermat primes: 1372930¹³¹⁰⁷² + 1 (804,474 digits) and 1176694¹³¹⁰⁷² + 1 (795,695 digits).

Join a discussion forum about prime numbers.

Participants in the project should have at least a 600 Mhz PC. To join the project, first download George Woltman's PRP software for Windows or Linux. Then send email to William Garnett with your CPU type and speed and your operating system, and he will send you instructions for participating.

Join a discussion forum about the project.

The project began its k=33661 project on November 21, 2002, and added fifteen additional projects on November 23, 2002. It has found the following primes:

The recent discovery of the 11th prime for the project helped prove a new mathematical theorem: the Mixed Sierpinski Problem. The results were published in a paper in the journal INTEGERS on December 23, 2008.

To participate in the project, sign up for an account, download the client, add your account name to the client configuration, and run it. The client does Proth tests on individual numbers. Each number should take a few hours to test on an average machine. When the project server assigns you a number, it waits for up to 10 days for you to return your search results, and reassigns the number to someone else if it doesn't receive your results within that time.

The client supports users behind firewalls and proxy servers. Version 2.5 of the client is available for Windows and Linux as of September 10, 2005. Version 2.5 of the client is available for FreeBSD as of 2006. Version 2.2 of the client is available for BeOS as of December 11, 2004. A new client based on the Prime95 client is available for Windows, Mac OSX and Linux as of March 18, 2009. This client has significant improvements in speed and efficiency.

Seventeen or Bust also has a supporting project to sieve numbers for the main project: sieving finds n numbers with small factors and removes them from the pool of prime number candidates which need to be tested by Seventeen or Bust. Two clients are available for sieving: SoBSieve (for Windows) and NBeGone (for multiple platforms). To reserve a range of numbers to sieve, post a message to the sieve coordination thread. Then submit the results from the range to the "sieve numbers" page mentioned above. The latest sob.dat file, with 10 k, is available as of January 3, 2005.

As of January 9, 2005, users with regular user accounts can also perform second-pass tests of numbers the project has already tested once. This feature will be included in a future client, but for now it requires a bit of hacking for the Windows client. See details in this thread and participate at your own risk.

See the project's Wiki.

Join a discussion forum about the project.

The Phi(92) series was completely factored by November 2, 2002: the last composite number was factored by Tetsuya Kobayashi on that date. Katsuyuki Okeya finished the Phi(61) and Phi(122) series on December 30, 2002. The Phi(69) series was completely factored by January 12, 2003: the last composite number was factored by Alexander Kruppa. The Phi(112) series is completely factored as of September 25, 2004. The Phi(144) series is completely factored as of October 12, 2004. The Phi(104) series is completely factored as of November 30, 2004. The Phi(168) series is completely factored as of December 24, 2004. The Phi(180) series is completely factored as of January 18, 2005. The Phi(65) series is completely factored as of February 9, 2005. The Phi(130) series is completely factored as of February 26, 2005. The Phi(156) series is completely factored as of March 6, 2005. The Phi(210) series is completely factored as of March 22, 2005. The Phi(53) series is completely factored as of July 1, 2006. The Phi(198) series is completely factored as of September 13, 2008. The Phi(118) series is completely factored as of September 22, 2008.

To participate in the project, you can download and compile a GMP or UBASIC factorization program, view a page of reserved numbers, then select a range of numbers to factorize and send email to Hisanori Mishima with the range information.

Read a paper about cyclotomic polynomials and prime numbers by Yves Gallot.

The client software consists of a server application which must be run on a GNU/Linux system with a version 2.4 or later kernel, and a client application which may be run on the same GNU/Linux system or on other GNU/Linux or Windows NT/2000/XP systems which can communicate with the server application over an intranet. As of May, 2005, "it is now possible to run the client program in "batch mode" in Windows. No server on GNU/Linux required. It will be necessary to manage things manually. The windows client program acts as a service. In particular, it does not run on a DOS windows. It runs invisibly in the background (at a very low priority)." To participate in the project, send email to Tomás Oliveira e Silva, the project coordinator, with information about the machine(s) on which you will run the server and client applications, and he will send you more information about how to participate.

To participate download the proth.exe client, view reserved ranges on the checked out and progress page, then reserve a range (and submit your results) on the range reservation page. The latest public Beta version of LLRNet is available as of April 5, 2004.

The project has found the following primes recently:

Prime	Digits	Date
3 * 2234760 - 1	70,671	April 11, 2003
3 * 2414840 - 1		May 6, 2003
3 * 2584995 - 1		August 19, 2003
3 * 2702038 - 1		November 19, 2003
3 * 2727699 - 1		January 26, 2004
3 * 2992700 - 1	298,833	May 15, 2004
3 * 21201046 - 1	361,552	August 24, 2004
3 * 21232255 - 1	370,947	August 30, 2004
3 * 22312734 - 1	696,203	December 20, 2005
3 * 23136225 - 1	944,108	March 8, 2007

To participate, download one of the following software clients: LLR, PFGW, PRP (see download links in the discussion forum), then reserve a range from the 3-4M reservations page and download a zip file of all the input files from a link on that page. After you run the client, email the results to Paul Underwood. Version 3.7.1 of LLR (available here) is available as of May 4, 2006. The latest sieved files are available as of February 23, 2007.

Join a discussion forum about the project.

On November 10, 2002, NFSNET completed the factorization of W(668), a 204-digit special number field sieve (SNFS).

The client is command-line, with a GUI wrapper client available. It is better for users with permanent Internet connections. It supports users behind firewalls but not users behind proxy servers. Release Candidate 1 of the client is available as of May 12, 2003.

The project's 10 most recent factorizations:

Number	Began	Sieving Completed	Factorization Completed	Stats
7254 + 1	February 19, 2005	March 22, 2005	April 10, 2005	stats
11208 + 1	March 22, 2005	April 3, 2005	April 10, 2005	stats
11212 + 1	April 3, 2005	May 22, 2005	June 22, 2005	stats
2751 + 1	May 22, 2005	July 18, 2005	in progress	stats
2760 + 1	July 17, 2005	July 27, 2005	August 4, 2005	stats
2736 + 1	July 26, 2005	September 5, 2005	October 5, 2005	stats
2719 + 1	September 5, 2005	September 28, 2005	October 30, 2005	stats
2761 - 1	September 19, 2005	November 24, 2005	January 22, 2006	stats
2764 + 1	November 19, 2005	February 7, 2006	May 1, 2006	stats
2,1466L	February 7, 2006	March 27, 2006	March 30, 2006	stats
3479 + 1	March 30, 2006	in progress	not yet started	stats
2797 + 1	March 30, 2006	unknown	July 3, 2006	stats

Join a discussion forum about the project.

Subscribe to the project mailing list.

The project has recently proven the following numbers are prime:

Number	Digits	Date
166332!23 - 1	34,619	January 1, 2010
177871!23 - 1	37,246	January 7, 2010
172344!23 - 1	35,986	January 7, 2010
171232!23 - 1	35,733	January 7, 2010
229345!23 - 1	49,125	January 28, 2010
417240!23 + 1	94,083	February 7, 2010
432801!23 + 1	97,892	April 10, 2010
431414!23 + 1	97,892	April 10, 2010
419499!23 + 1	97,892	April 10, 2010
234676!7 + 1	165,489 (new multifactorial record)	April 15, 2010
284400!7 + 1	203,944 (new multifactorial record)	May 27, 2010

On March 29, 2005, the project finished !19 to 200,000. On May 31, 2005, the project finished !17 + 1 to 170,000. On August 6, 2005, the project finished !17 - 1 to 170,000. On August 21, 2005, the project finished !25 to 200,000. On September 9, 2005, the project finished !15 to 130,000. On November 26, 2005, the project finished !15 to 150,000. On November 26, 2005, the project tested all types up to 20 to 10,000 * type +/- 1. On December 20, 2005, the project finished !3 + 1 to 75,000. On February 28, 2006, the project finished !24 + 1 to 240,000. On March 27, 2008, the project finished !25 + 1 to 250,000. On July 8, 2010, the project finished !12 - 1 to 160,000.

Participation instructions are at the top of the project page. Basically, you email the project coordinator to reserve a type, then use the multisieve and pfgw Windows applications to sieve the range and find primes in it, then submit your results to the project coordinator.

The project has found the following prime numbers recently:

165054615 * 2223395 - 1	October 10, 2005
504017085 * 2246861 - 1	October 10, 2005
545544285 * 2232438 - 1	October 10, 2005
355424355 * 2456781 - 1	October 11, 2005
2 primes for k=9345	October 15, 2005
736320585 * 2339426 - 1	October 16, 2005
2190435975 * 2204857 - 1	October 18, 2005
743411955 * 2210282 - 1	October 18, 2005
2 primes for k=773021535	October 18, 2005
2 primes for k=245630385	October 18, 2005

See all of the primes the project has found.

To participate, follow the instructions for how to join, then the instructions for how to participate (novice or expert). The project uses the LLR.exe, NewPGen.exe and RMA.NET software executables. Note that you will need to download the Microsoft .NET runtime library if you don't already have it installed. Version 0.82 of RMA.NET is available as of December 3, 2005.

Join a discussion forum about the project. See the project's wiki.

On February 1, 2004 the project "found a 42 digit factor of M(5280) using GMP-ECM with B=3M. This is expected to qualify for 9th place in Paul Zimmerman's Top Ten This Year list." On April 4, 2004, the project found P35, the first known primitive factor of M(15840). On May 14, 2004, the project found P34, the second known factor of M(10395). On June 9, 2004, the project found P25, the second known factor of the primitive part of M(66528). On June 12, 2004, the project found a P49 factor for M(1485), the largest factor found by ElevenSmooth using ECM. On July 20, 2004, the project completed the factorization of M(3960). On September 18, 2004, the project found a P28 factor of M(95040): this is the first known factor of the primitive part of M(95040). On October 19, 2004, the project found a P36 factor of M(11880), "the second known factor for the primitive part of this number." On July 28, 2005, the project found a P35 factor of M(47520), the third factor the project has found for the primitive part of M(47520). In early December, 2005. the project found a 41-digit factor of M(6336). In March, 2008, the project completed the factorization of M(1575). On May 7, 2008, the project completed the factorization of M(2376). On July 16, 2008, the project found a P34 factor of M(5400) (using ECM at the B1=1M level). This factor reduces the unfactored residual from C406 to C373. This is the second factor ElevenSmooth has found for this number. On November 15, 2008, the project found a P37 factor of M(100800). This factor reduces the unfactored residual from C6925 to C6889. On March 27, 2009, the project found a P51 factor of 2³³⁶⁰ + 1. This is the largest factor ElevenSmooth has found by ECM and is the fourteenth primitive for which ElevenSmooth has completed the factorization. See news of more recent factor discoveries on the project's main page.

To participate in the project, download the ECMclient application and configure it according to the directions on the download page (if you already have the ECM or ECMclient application installed, you only need to reconfigure it to use server=wblipp.dynu.com and port=8194). Unix users can follow instructions to create an ECM client for Unix. Once ECMclient is configured, it contacts the ElevenSmooth project server to get work units and to return results. It processes a work unit for 30 minutes by default, but you can change the processing time by changing the maxfreq parameter. The project supports users behind firewalls and possibly proxy servers. It supports modem users with a little bit of work. See the help page for information about using firewalls, proxy servers, and modems.

The project also has a Special Project sub-project for users who have contributed at least one full week to the main ECM project. The Special Project "uses GIMPS' program Prime95 to work on all primitives of M(3326400) simultaneously. If any ECM work is going to be done on the largest composites, Prime95 is much faster. The subfactor composites are then tested 'for free.' However, even with Prime95, it takes a long time to run ECM curves on large numbers." Users who qualify for this project will be invited by email to join it.

See the project's progress and completed factorizations.

Join a discussion forum about the project.

Note: the project website was unreachable between July, 2008 and October, 2008. The status of the project is unknown. Look for news updates in the News column of the PrimeGrid project main web page and in the Riesel Sieve "backup forums."

As of February 18, 2005, the project has sieved all of its ks to 100T. As of June 18, 2005, the project has 5,488,686 k/n pairs left to test. As of March 22, 2006, the project has completed the 2^20 to 2^21 stage of its first run. As of February 27, 2007, the project has sieved all of its ks to 500T.

On September 16, 2005, the project offered a US$100 prize to the person who found the next prime for the project. Project participant NeoLogic found the prize-winning prime, 357659 * 2^1779748 - 1, on September 24. On September 26, the project began a Prime Bounty Contest, which rewards both prime hunter and sieve participants in the project. On September 28, 2005, the project began a Riesel Sieve Prime and Sieve Bounty donation fund at fundable. This fund will be used for rewards for project participants who find primes and who sieve significant factors for the project, according to the contest rules.

The project has found the following prime numbers recently:

417643 * 21800787 - 1	October 5, 2005
467917 * 21993429 - 1	December 24, 2005
450457 * 22307905 - 1	March 28, 2006
196597 * 22178109 - 1	May 9, 2006
114487 * 22198389 - 1	May 23, 2006
275293 * 22335007 - 1	September 22, 2006
26773 * 22465343 - 1	December 1, 2006
342673 * 22639439 - 1	April 24, 2007
469949 * 21649228 - 1	October 28, 2007
113983 * 23201175 - 1	May 1, 2008

The project offers the independent LLRNet client and a BOINC-based Sieve client.

To participate in the project, follow the BOINC Sieve client instructions, or use the LLRNet client to automatically download ranges of numbers and to submit results (see instructions for using it), or view instructions on the download page to use the rieselsieve.exe client. Basically you download the rieselsieve.exe executable and the riesel.dat data file (about 6 MB compressed and 27 MB fully expanded). Then you reserve a range of numbers through the automated reservation page, process them with rieselsieve.exe, and submit your resulting factors. The riesel.dat file is updated regularly and gets smaller as prime candidates are removed.

Version 0.42 of the Proth_sieve client is available for Windows and Linux as of February 12, 2004. This version is 5-10% faster than the previous version. A client should be available for FreeBSD soon. Version 3.5 of LLRNet is available as of May 2, 2005. Version 5.27 of the BOINC Sieve client is available for Windows as of August 27, 2006. The riesel.dat file was last updated on December 3, 2006. An updated Windows GUI client should be available soon.

See the project's wiki.

Join a discussion forum about the project.

The project's first anniversary was on November 8, 2004. By that date it eliminated 11 k's by finding 11 large primes, and also sieved to almost 40 trillion. In the next year it hopes to reach at least n=2.5 million for PRP, to find serveral new primes, and to sieve to 100 trillion. As of October 1, 2005, it has tested all n below n=1600000 at least once. With help from PrimeGrid, the project's sieve entered the 10P range by September 30, 2008.

The project has found the following prime numbers recently:

159503 * 2540945 + 1	February 7, 2004
263927 * 2639599 + 1	February 20, 2004
261917 * 2704227 + 1	March 8, 2004
161957 * 2727995 + 1	March 22, 2004
216751 * 2903792 + 1	May 10, 2004
241489 * 21365062 + 1	January 24, 2005
149183 * 21666957 + 1	October 7, 2005
214519 * 21929114 + 1	January 2, 2006
222361 * 22854840 + 1	August 31, 2006
265711 * 24858008 + 1	April 5, 2008

To participate in the project, read the Getting Started discussion thread, then download and run the network LLR client. The client automatically reserves work units and submit results.

Join a discussion forum about this project.

To participate in the project, send email to the project owner, user "thefatphil" at host "yahoo.co.uk", to let him know you're interested. Then download the client and follow the instructions on the download page for running it. Version 0.7 of the client is available for Windows. Version 0.8 is available for Linux, FreeBSD, AIX and Irix.

See the 50 most recent factors.

As of September 5, 2004, the project has reached n=500 for all k=11. The project now includes numbers for k=13, also factored up to n=500. "Numbers for k=13, n > 500 have had very little ecm done on them."

The doecm client downloads composites and submits results automatically, but you can manually reserve numbers and submit factors through the website. Version 1.01 of the client is available for Windows and Linux. You can also download and compile the source code for the client.

The project completed the factorization of all numbers with y < 11 as of February 7, 2005. It completed the factorization of all numbers up to x = 90 as of March 16, 2005. It completed the factorization of all numbers with y < 16 as of April 27, 2005. The number of composites was reduced to 2500 as of September 10, 2005. It completed the factorization of all numbers with y <= 100 as of October 28. The number of composites was reduced to 2300 as of October 18, 2007. It completed the factorization of all numbers up to x = 100 as of October 28, 2007. The number of composites was reduced to 1800 as of November 25, 2009.

The project added a Primes and PRPs of the form x^y + y^x page to its website on June 6, 2008.

The project has factored the following numbers recently:

10392 + 92103	September 28, 2006
14832 + 32148	March 12, 2007
15048 + 48150	September 9, 2007
14197 + 97114	December 18, 2007
13144 + 44131	February 14, 2008
114103 + 103114	May 29, 2008
12465 + 65124 (largest factorization record 225 digits)	January 5, 2009
14325 + 25143	February 11, 2009
11882 + 82118 (GNFS record 147 digits)	May 25, 2009
12293 + 93122 (SNFS record 241 digits)	November 19, 2009

The project has also factored the following numbers recently:

C251_124_105 = P41 * C210	August 16, 2005
C168_110_63 = P57 * P112 (ECM record 57 digits)	January 13, 2009

You can reserve numbers manually through the project website and factor them with your favorite factoring client application (GMP-ECM is reocmmended), or you can use the ECMclient application and automatically reserve numbers and submit results (use the ecmserver childers.myip.org, port 34). Version 6.0 of GMP-ECM is available as of February 28, 2005. Version 2.5.6 of ECMclient is available as of March 16, 2005. Version 1.39 of MSieve, another client which can be used for the project, is available as of December 2, 2008. As of November 19, 2004, there are 3,242 XYYXF composites from C93 to C321. 761 of them are reserved; 2,481 (including 123 more wanted) are available. Due to a massive SNFS attack, only 38 new numbers were added to the "most wanted" list for 2005.

Join a Yahoo! Group discussion forum about this project.

To participate in the project, download Luigi Morelli's factor3_2.exe client and some Cygwin files from the project web page, then reserve an unassigned exponent in the project's discussion forum. Version 2 of the client is currently available. It is 25% faster than the previous version.

Join a discussion forum about this project. See the project's latest progress updates.

To participate in the project, sign up for an account on the website, then reserve ranges and submit results through the website. Use either the proth or primeform application: links to these applications are on Prime Links++ to process your reserved ranges.

To participate, read the instructions in the How to start? discussion thread.

Note: this project only has a discussion forum and no website.

Factoring completed the factorization of 2^791+1 (to 45 digits) on May 2, 2005. It completed the factorization of 2,1342L on May 8, 2005. It achieved a new P - 1 record, 2,2098M c281 = p58 * c224, on September 28, 2005.

Factoring Projects:

Project	Began	Ended	Curves Completed
M1061	October 14, 2004	in progress	1185 of 22000
HP49(100)	October 24, 2004	in progress
P16384	October 31, 2004	in progress
R311	December 12, 2004	in progress found 64-digit factor 43446730587149544777613147934373 92900672885445361103905548950933, 2nd-largest ever using ECM, on September 5, 2005
M8151	December 29, 2004	in progress	B1 11000000: 3890 of 10600 B1 44000000: 1801 of 19300
Factoring 43rd Term of Euclid-Mullin sequence	January 23, 2005	in progress

To participate, read the instructions in the forum.

Note: these projects only have a discussion forum and no websites.

To participate in the project, download Luigi Morelli's factor3_2.exe client and some Cygwin files, or Mfactor for win32, or 32-bit or 64-bit Linux, from links on the project web page. (See more information in the guide.) Then look for an available range or exponent in the table on the project web page and follow the instructions on the project web page to reserve the range or exponent and to submit results. Version 2 of the factor3_2 client is currently available. It is 25% faster than the previous version.

Join a discussion forum about this project.

To participate in the project, use the primeform application (follow the directions on the project page for using primeform), and send email to the project coordinator to reserve a range to check and to submit results.

To participate in the project, use one of the software clients listed on the project website. The project website does not contain details about how to use the clients or about how to reserve numbers and submit results. More information may be available in the project's discussion forum. Also see the project's wiki.

The project has found the following primes recently:

Prime	Date
57316 * 538250 + 1	May 26, 2005
159106 * 589982 + 1	May 29, 2005
53858 * 533760 - 1	June 3, 2005
98288 * 533760 - 1	June 6, 2005
214958 * 520254 - 1	June 21, 2005
43156 * 544135 - 1	June 22, 2005
294698 * 547110 - 1	June 23, 2005
18914 * 526012 - 1	July 12, 2005
9374 * 536046 - 1	July 17, 2005
9164 * 540892 - 1	July 19, 2005

To participate in the project, use NewPGen to sieve and PRP to test, and follow these instructions. As of October 15, 2006, a Linux version of the LLRNet client is available from http://base5.greenbank.org/. See instructions for using this client. Note that the reservation list reached the 10,000 character limit on October 15, 2005, so participants should follow the links to the sieve files on the reservations page.

The project passed 1 TeraFLOPS/second of computing power on February 27, 2006.

On September 12, 2006, the project began a new test project called SZTAKI Desktop Grid Research Facility (szdgr). This project will "improve the testing process of applications, thus improving user-experience (get rid of the credit problems, etc.) of SZTAKI Desktop Grid."

The project uses a BOINC-based client. See the BOINC platform information for the latest version of the BOINC client. Version 2.01 of the project's NumSys Search client is available for Windows as of October 16, 2006. Version 2.03 is available for Linux as of August 1, 2006. Version 2.00 is available for Mac OSX as of July 5, 2006.

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On February 28, 2007, the project reported its 100th prime to the prime pages.

On November 26, 2006, the project began working with Twin Internet Prime Search, and is supporting a second sub-project to help that project. It completed its search on August 6, 2009, with the discovery of twin primes.

On October 3, 2008, the project achieved "'optimal' sieve depth [in the Cullen/Woodall project] ...actually, a little beyond it. Therefore, we are stopping the 32 bit and 64 bit Cullen/Woodall Sieve applications and archiving the sieve. Cullen/Woodall LLR will remain active up to n=10M. For more information, please see this forum post."

On December 27, 2008, the project began a new sub-project, AP26 Search, "an Arithmetic Progression of 26 primes. An arithmetic progression of primes is a sequence of primes with a common difference between any two successive numbers in the sequence. For example 3, 7, 11 is an arithmetic progression of 3 primes with a common difference of 4."

On August 8, 2008, the project announced a "Dog Days of Summer Challenge." The three-day challenge ran from August 22-24 and supported PrimeGrid's 321 Prime Search LLR application. See more information in a forum thread about the challenge. On September 6, 2008, the project announced a "Back to the Future Challenge." The 14-day challenge ran from September 13-27 and supported the Woodall Prime Search for the next record Woodall prime. During the challenge, "over 8,000 Woodall [work units] were completed by 204 teams and 1108 individuals." See more information in the challenge's forum thread. On January 24, 2009, the project announced a "Year of the Ox Challenge." The 5-day challenge supported the project's 321 Prime Search (LLR) sub-project. See more information in the challenge's forum thread. The project began its Tour de Primes 2009 contest on February 1, 2009.

On February 14, 2009, the project announced a partnership with 12121 Search.

On April 20, 2009, the project's Cullen Prime Search found a World Record Cullen Mega Prime: 6328548 * 2^6328548 + 1 (1,905,090 digits). At that time this prime was the largest Cullen prime found and the largest Mega Prime found using LLR. On August 6, 2009, the project's Cullen Prime Search found its next World Record Cullen Mega Prime: 6679881 * 2^6679881 + 1 (2,010,852 digits).

The project uses a BOINC-based client. See the BOINC platform information for the latest version of the BOINC client. Version 5.13 of the project's Prime Generator client is available as of May 16, 2006. Version 5.04 of the project's LLR Prime Search client is available as of November 25, 2006.

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1. find k's that can produce many primes in the given range of exponent n
2. find low-weight k's that produce a very small number of primes [opposite to the sub-project above
3. find small k < 300 (with exception of those k's already reserved by other projects)

See the latest primes found by the project here and here.

To participate, look for (or ask for) instructions in the project forums. Note: this project only has a discussion forum and no website.

On May 21, 2008 the project began releasing W7 work units.

The project uses a BOINC-based client. See the BOINC platform information for the latest version of the BOINC client. Version 5.45 of the project's CAPE Crossing Number client is available for Linux as of August 3, 2006. Version 5.41 is available for Windows as of July 4, 2006. Version 5.49 of the project's TCAPE Crossing Number client is available for Linux and Windows as of August 5, 2006.

Join a discussion forum about the project.

The project uses a BOINC-based client. See the BOINC platform information for the latest version of the BOINC client. Version 1.00 of the project's ABC finder client is available for Windows and Linux as of January 13, 2007.

Join a discussion forum about the project.

The project uses a BOINC-based client. See the BOINC platform information for the latest version of the BOINC client. Version 1.06 of the project's "Random-base WEP Factorization" client is available for Linux/x86 as of January 4, 2007. Version 1.07 of the client is available for Linux/AMD64 as of January 21, 2007. Version 1.04 of the client is available for Mac OSX as of December 5, 2006.

Join a discussion forum about the project.

The project uses a BOINC-based client. See the BOINC platform information for the latest version of the BOINC client. Version 1.08 of the project's Cruncher application is available for Windows as of September 2, 2007. Version 1.07 is available for Linux/X86 as of August 30, 2007. Version 1.08 is available for Linux/X86-64 as of October 2, 2007. Version 1.07 is available for Mac OSX as of August 31, 2007. Version 1.08 is available for Solaris and FreeBSD as of September 30, 2007. Version 1.09 is available for PS3 as of September 30, 2007.

Join a discussion forum about yoyo@home.

PS3

See the best path discovered by the project today.

The project uses a BOINC-based client. See the BOINC platform information for the latest version of the BOINC client. Version 2.15 of the project's TravelingSalesmanProblem application is available for Windows, Linux, Mac OSX and FreeBSD as of November 28, 2007.

Join a discussion forum about this project.

To participate in the project, download and run the project's software client. Version 2.0 of the client is available for Windows as of February 4, 2008. This version "accelerates searching in complete and periodical test. Software makes use of totally new algorithms, which are very efficient for mathematical method: exponentiation and congruency. New units for complete test are 10x larger and in periodical test 1.5x larger."

Join a discussion forum about this project.

To participate in the project, follow instructions in the project's Software/instructions/questions discussion thread. The project uses the LLR, NewPGen, Sr1sieve, Sr2sieve, Srfile, and Srsieve applications.

Join a discussion forum about this project.

To participate in the project, send email to the project owner to reserve a range, then download NewPGen version 2.82 for pre-sieveing and LLR version 3.71c for finding primes (you can download these applications from http://gbarnes017.googlepages.com/primebehindprogs.zip or from links listed in other projects above), then search for prime numbers within that range, then email the results to the project owner.

The project uses a BOINC-based client. See the BOINC platform information for the latest version of the BOINC client. See the project's Applications page for information about the client applications and versions the project is using.

Join a discussion forum about this project.

The project uses a BOINC-based client. See the BOINC platform information for the latest version of the BOINC client. See the project's Applications page for information about the client applications and versions the project is using.

Join a discussion forum about this project.

See the project's progress page for its latest results.

The project uses a BOINC-based client. See the BOINC platform information for the latest version of the BOINC client. See the project applications page for the latest version of the ECM client.

Join a discussion forum about yoyo@home.

The project finished on June 8, 2010. The project began another Euler625 project on June 12, 2010. The new project, which searches up to 250,000, needs testers for its Linux clients.

See the latest solutions found by the project.

The project uses a BOINC-based client. See the BOINC platform information for the latest version of the BOINC client. See the project applications page for the latest version of the Euler (6,2,5) client.

Join a discussion forum about yoyo@home.