June 23, 2011
New Fermat factor discovered after 1 day!
7333*2^138560+1 is a Factor of F138557!!!.
The factor was discovered by Dirk D'huyvetters of Belgium coadiuvated by the PrimeGrid team. This is the 288th known divisor fifth factor found this year.
This factor was the first of the three disconvered in March, but only during the recent double-checking for GFN divisibilities the factor was revealed, as the team was focused on Proth Primes and not Fermat factors.
Congratulations go to Dirk and to the leading organizers of PrimeGrid: John Blazek, Rytis Slatkevičius and Lennart Vogel!
June 22, 2011
New record-size Fermat factor!
As part of PrimeGrid's Proth Prime Search, Scott Brown (USA) found the following new factor of a Fermat number: 9*2^2543551+1 is a Factor of F2543548!!!.
This factor 765,687 digits long exceeds in size the prime factor 3* 2^2478785+1 of F2478782 discovered on October 10, 2003 and therefore is currently the largest known divisor of a Fermat number!
Congratulations to everyone involved in this remarkable discovery!!
March 20, 2011
New Fermat factor after 5 days!
111318179143061*2^45+1 is a Factor of F42!!!.
The factor was discovered by Roman Maznichenko from Russia using Mark Rodenkirch's GMP-Factor. This is the first factor found by GMP-Factor.
Roman worked hard on ECM also, and we all hope he will find another factor soon.
March 15, 2011
Second Fermat factor of 2011!
14783975791554494074552473179612897725474511*2^19+1 is a Factor of F17!!!.
The factor was discovered by David Bessell from St Michael's Collegiate School in Australia using Prime95. This is the third factor found by David while computing ECM curves on small Fermat numbers.
The cofactor of F17 has around 39,000 digits, and has been proven composite.
February 21, 2011
FermatSearch.org has a new server ! To guarantee better performances to our users, your webmaster has taken the opportunity to upgrade the old hardware and install a new more powerful one. Please let me know about every possible glitch that may have occurred during the migration of data.
February 5, 2011
GMP-Fermat 2.1 for Windows 64 bit version has passed its checks!!!.
Thanks to Matt Anderson (who addressed the issue on MersenneForum) and Brian Gladman (who offered his programming skills), we now finally have a GMP-Fermat version with superfast assembly routines written by Geoff Reynolds and running on Windows 64-bit platforms!
The new executable can be found on the Download page. Wonderful job, Brian and Matt, thank you!
January 12, 2011
First Fermat factor of 2011!
837747239*2^1203+1 is a Factor of F1201!!!.
The factor was discovered by our old friend Maximilian Pacher, from Austria, using NewPGen, PRP and PFGW programs. Maxi could have found this factor seven years ago if his range were not limited to 1200.
This is his fourth Fermat factor"
December 9, 2010
GMP-Fermat 2.1 for Windows 64 bit version is out!!!.
Thanks to Matt Anderson (who addressed the issue on a forum) and Brian Gladman (who offered his programming skills), we now finally have a GMP-Fermat version with superfast assembly routines written by Geoff Reynolds and running on Windows 64-bit platforms!
The new executable can be found on the Download, http://www.fermatsearch.org/download.html
, page. Wonderful job, Brian and Matt, thank you!
November 20, 2010
A second new Fermat factor has been found on November 20!
272392805475*2^304+1 is a Factor of F299!!!.
The factor was discovered by Alexey Komkov, from Russia, using his own program written in Borland C++ builder. Alexey has been testing a huge range using 30 P4 computers in the last 6 months.
November 8, 2010
A totally new Fermat factor has been found!
103257279*2^2422+1 is a Factor of F2420!!!.
The factor was discovered by Peter Strasser, from Austria, on November 7th, 2010. Peter was testing a huge range with his own program based on Mathematica.