Record AP24 Found
2009-04-07 15:30 UTC

PrimeGrid has found a record AP24 (Arithmetic Progression of 24 primes). It is the largest known AP24. It has an ending term of 19898154930924749 surpassing the old record of 19516877252820799. The finder is Pawel Stachowiak (stachu @ fiddex),

http://www.primegrid.com/show_user.php?userid=27426 , of Poland. The progression is written as 7960592659339799+2326495*23#*n for n=0..23. It was found in the AP26 Search.

For more details on this find and the AP26 search, please see this forum post,

http://www.primegrid.com/forum_thread.p ... true#14719 .

New AP24 Found
2009-04-05 19:30 UTC

PrimeGrid has found a "New" Arithmetic Progression of 24 primes. The finder is Pawel Stachowiak (stachu @ fiddex),

http://www.primegrid.com/show_user.php?userid=27426 , of Poland. The progression is written as 6274259724784693+2522655*23#*n for n=0..23. It was found in the AP26 Search. We expect to find many more and even a few AP25's along the way to the goal of an AP26.

For more details on this find and the AP26 search, please see this forum post,

http://www.primegrid.com/forum_thread.p ... true#14676 .

321 Prime Search finds a Mega Prime
2009-04-05 07:20 UTC

On 3 Apr 2009 15:40:01 UTC, PrimeGrid's 321 Prime Search found another Mega Prime:

3*2^5082306+1

The prime is 1,529,928 digits long and enters Chris Caldwell's The Largest Known Primes Database,

http://primes.utm.edu/primes/ , ranked 15th overall. It is the 6th largest Proth prime found and the largest found Mega Prime using LLR.

The discovery was made by Andy Brady (Andy Brady),

http://www.primegrid.com/show_user.php?userid=1599 , of the United States using an Intel C2Q Q8200 @ 2.33GHz with 3GB RAM running Windows Vista. This computer took about 14 hours 7 minutes to complete the primality test. Andy is a member of the BOINCstats,

http://www.primegrid.com/team_display.php?teamid=1 , team.

For more details, please see the official announcement,

http://www.primegrid.com/download/321-5082306.pdf . Decimal representation of the number is also available,

http://www.primegrid.com/download/321n5082306.pdf .

321 Prime Search finds a Mega Prime
2009-04-04 14:10 UTC

A PrimeGrid participant has discovered a Mega Prime in the 321 Prime Search! We are currently GFN divisibility testing the prime as well as awaiting contact with the discoverer. It is a top 15 prime and the largest found by LLR. Stay tuned for more details.

Fermat Number Divisor
2009-04-02 01:30 UTC

Congratulations to Eric Embling (Eric E),

http://www.primegrid.com/show_user.php?userid=35693 , of the United States, the discoverer of PrimeGrid's third Fermat Number divisor in the Proth Prime Search project: 659*2^617815+1 Divides F(617813). It is the 3rd found Fermat Number divisor of 2009 and 273rd overall. It is the 6th largest Fermat Number divisor in Chris Caldwell's The Largest Known Primes Database. Incidentally, it is a new record for "weighted" Fermat Number divisors

For more information, please see this forum post,

http://www.primegrid.com/forum_thread.p ... true#14635 .