Call for arms: full doublecheck of TRP
We have recently started a limited doublecheck effort for The Riesel Problem and this has very quickly yielded a prime, which means that the results that we obtained from Riesel Sieve project cannot be trusted 100%. Therefore we have decided to run a full doublecheck effort.
We would like to quickly go through the doublecheck ranges and resume our original search, so we would like to ask you to consider redirecting any resources you may have available to The Riesel Problem (TRP) subproject. You can do that by visiting project preferences page.
Applications are available for Windows, Linux and Mac. 32bit applications will be sent to 64bit hosts.
3 Feb 2012 | 12:22:23 UTC
· Comment
Prime found for the Riesel Problem
On 2 Feb 2012, 21:30:55 UTC, PrimeGrid’s The Riesel Problem project eliminated k=162941 by finding the prime: 162941*2^993718-1
The prime is 299,145 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 1536th overall. This prime was found while exploring a suspected gap in a previously searched range. This is PrimeGrid's 8th elimination. 56 k's now remain.
The discovery was made by Dmitry Domanov (unconnected) of Russia using an Intel Xeon @ 3.60GHz with 2 GB RAM running Windows Server 2003 Enterprise x86. This computer took just over 1 hour 5 minutes to complete the primality test using LLR. Dmitry is a member of Team Russia.
For more details, please see the official announcement.
3 Feb 2012 | 5:02:47 UTC
· Comment
The Tour de Primes Begins!
Come join us in laid-back competition in tribute to the number 2...the first prime and the only even prime. The prizes are simple colored jerseys . Yellow for the most primes, Green for the highest prime score, and Polk-a-dot for the most primes on 19 Feb. No pressure or stress other than what you put on yourself. :) For more information, please see Tour de Primes 2012.
1 Feb 2012 | 0:29:32 UTC
· Comment
World Record Generalized Cullen Prime
On 29 Jan 2012, 08:10:03 UTC, PrimeGrid’s PRPNet found the largest known generalized Cullen prime: 427194*113^427194+1
The prime is 877,069 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for generalized Cullen primes and 57th overall.
The discovery was made by Ricky L. Hubbard of the United States using an AMD Phenom II X6 1090t @ 3.2GHz with 8GB RAM, running Windows 7. This computer took 7 hours and 15 minutes to complete the probable prime test using pfgw64 and 7 hours 20 minutes to complete the primality test again using pfgw64. Ricky is a member of the AMD Users Team.
For more details, please see the official announcement.
30 Jan 2012 | 2:12:11 UTC
· Comment
Tour de Primes 2012
February is just a week away which means it is time for the 4th annual Tour de Primes. 2 is the first prime number...and the only even one. Therefore, we have declared February, the 2nd month, as prime month.
We're offering a small informal competition in tribute to this unique prime number. There are no points to be gained or awards to be won...just a simple rare jersey (Yellow, Green, and Polk-a-dot) at the end of the month to add to your badge collection. No pressure or stress other than what you put on yourself. :) For more information, please see Tour de Primes 2012.
24 Jan 2012 | 16:23:12 UTC
· Comment
... more
News is available as an RSS feed 
