PrimeGridʼs
Generalized Fermat Prime Search	  On 08 Mar 2011 10:35:34 UTC, PrimeGrid’s PRPNet found a GeneralizedFermat mega prime:
40734262144+1
The prime is 1,208,473 digits long and enters Chris Caldwell's “The Largest
Known Primes Database” (http://primes.utm.edu/primes) ranked 2nd forGeneralized Fermat primes and 26th overall.
The discovery was made by Senji Yamashita of Japan using an Intel Core 2
Quad Q9450 @ 2.66GHz with 2GB RAM, running Windows 7 Professional 64bit.
This computer took about 8 hours to complete the probable prime (PRP) test withGenefX64 and 4 hours and 29 minutes to complete the primality test usingpfgw64.
The credits for the discovery are as follows:
1. Senji Yamashita (Japan), discoverer
2. PrimeGrid, et al.
3. AthGFNSieve, sieve program developed by David Underbakke
4. GenefX64, probable prime program developed by David Underbakke
5. PFGW, primality program developed by Chris Nash & Jim Fougeron withmaintenance and improvements by Mark Rodenkirch
Entry in “The Largest Know Primes Database” can be found here:
http://primes.utm.edu/primes/page.php?id=99092
This is only the 3rd known GFN prime at N=262144. Using a single PC would
have taken years to find this prime. So this timely discovery would not have beenpossible without the hundreds of volunteers who contributed their spare CPUcycles. A special thanks to everyone who offered their advice and/or computing
power to the search - especially David Underbakke, Mark Rodenkirch and Geoff
Reynolds who were major forces in moving the project forward. Also, thank you
to all the sievers, especially Honza Cholt, and PRPNet’ers who contributed to thiseffort.
This is PrimeGrid’s 11th mega prime. The Generalized Fermat Prime Search willcontinue to seek even larger primes. To join the search please visit PrimeGrid:
http://www.primegrid.com

	  About PrimeGrid

PrimeGridʼsGeneralized Fermat Prime Search

PrimeGrid is a distributed computing project, developed by Rytis Slatkevičius,Lennart Vogel, and John Blazek, which utilizes BOINC and PRPNet to search forprimes. PrimeGrid's primary goal is to bring the excitement of prime finding to the"everyday" computer user. Simply download the software and let your computer
do the rest. Participants can choose from a variety of prime forms to search. Witha little patience, you may find a large or even record breaking prime.
BOINC
The Berkeley Open Infrastructure for Network Computing (BOINC) is a
software platform for distributed computing using volunteered computerresources. It allows users to participate in multiple distributed computing
projects through a single program. Currently BOINC is being developed bya team based at the University of California, Berkeley led by David
Anderson.
This platform currently supports projects from biology to math to astronomy.
For more information, please visit BOINC: http://boinc.berkeley.edu
PRPNet
PRPNet is a client/server application written by Mark Rodenkirch that is
specifically designed to help find prime numbers of various forms. It is easily
ported between various OS/hardware combinations. PRPNet does not run
each PRP test itself, but relies on helper programs, such as LLR, PFGW,phrot, wwww, and genefer to do the work.
For more information, please visit PrimeGrid’s PRPNet forum thread:
http://www.primegrid.com/forum_thread.php?id=1215
For more information about PrimeGrid and a complete list of available primesearch projects, please visit: http://www.primegrid.com