PrimeGrid’sProth Prime Search
On 18 June 2013 16:51:36 UTC, PrimeGrid's Proth Prime Search project found a prime Fermat
divisor:2145*21099064+1 Divides F(1099061)
The prime is 330,855 digits long and will enter Chris Caldwell's "The Largest Known Primes
Database" (http://primes.utm.edu/primes) ranked 10th for prime Fermat divisors and 2629thoverall. Incidentally, it is also a new record for "weighted" prime Fermat divisors.
The discovery was made by Sai Yik Tang of Malaysia using an Intel(R) Core(TM) i5-2400 CPU @3.10GHz with 4GB RAM running Microsoft Windows 7 Enterprise. This computer took about 8
minutes to complete the primality test using LLR.
The prime was verified on 21 June 2013 1:43:48 UTC by Timothy Hitch using an Intel(R)Core(TM)2 Duo CPU T8300 @ 2.40GHz with 4 GB RAM running Microsoft Windows 7 Ultimate.
This computer took about 33 minutes to complete the primality test using LLR.
The credits for the discovery are as follows:

1. Sai Yik Tang (Malaysia), discoverer
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PrimeGrid, et al.
Srsieve, sieving program developed by Geoff Reynolds
PSieve, sieving program developed by Ken Brazier and Geoff Reynolds
LLR, primality program developed by Jean Penné
OpenPFGW, a 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=114458.
Fermat number divisibility (including generalized and extended) was checked by OpenPFGW
using the following settings: -gxo –a2 12145*2^1099064+1 . For more information about Fermat
and generalized Fermat number divisors, please see Wilfrid Keller's sites: http://www.prothsearch.net/fermat.html
 http://www1.uni-hamburg.de/RRZ/W.Keller/GFNfacs.html
No generalized or extended generalized Fermat number divisors were discovered.
Using a single PC would have taken years to find this prime. So this timely discovery would nothave been possible without the thousands of volunteers who contributed their spare CPU cycles.
A special thanks to everyone who contributed their advice and/or computing power to the search especially all the sievers who work behind the scenes to make a find like this possible.
The Proth Prime Search will continue to search for more primes. To join the search please visit
PrimeGrid: http://www.primegrid.com

PrimeGrid’sProth Prime Search
About PrimeGrid
PrimeGrid is a distributed computing project, developed by Rytis Slatkevičius, Lennart Vogel, andJohn Blazek, which utilizes BOINC and PRPNet to search for primes. PrimeGrid's primary goal isto bring the excitement of prime finding to the "everyday" computer user. Simply download thesoftware and let your computer do the rest. Participants can choose from a variety of prime formsto search. With a 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 computer resources. It allows users toparticipate in multiple distributed computing projects through a single program. Currently
BOINC is being developed by a team based at the University of California, Berkeley led byDavid Anderson.
This platform currently supports projects from biology to math to astronomy. For more
information, please visit BOINC: http://boinc.berkeley.edu
PRPNetPRPNet is a client/server application written by Mark Rodenkirch that is specificallydesigned 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, 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 prime search projects,
please visit: http://www.primegrid.com