Free-DC
10-26-2015, 01:26 AM
On 21 October 2015, 05:23:34 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=100186 by finding the mega prime: 100186*5^2079747-1 (http://primes.utm.edu/primes/page.php?id=120481) The prime is 1,453,686 digits long and enters Chris Caldwell's The Largest Known Primes Database (http://primes.utm.edu/primes) ranked 53rd overall. This is the largest known base 5 mega prime. 78 k's now remain in the Riesel Base 5 Problem. The discovery was made by Toshitaka Kumagai (Toshitaka Kumagai (http://www.primegrid.com/show_user.php?userid=195534)) of Japan using an Intel(R) Xeon(R) CPU E3-1220 V2 @ 3.10GHz with 32GB RAM running Linux. This computer took about 15 hours 41 minutes to complete the primality test using LLR. The prime was verified on 21 October 2015, 18:46:14 UTC by Scott Brown (Scott Brown (http://www.primegrid.com/show_user.php?userid=1178)) of the United States using an Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz with 8GB RAM running Microsoft Windows 7 Enterprise. This computer took about 27 hours 36 minutes to complete the primality test using LLR. Scott is a member of the Duke University (http://www.primegrid.com/team_display.php?teamid=154) team. For more details, please see the official announcement (http://www.primegrid.com/download/SR5-100186.pdf).
More... (http://www.primegrid.com/forum_thread.php?id=6500)
More... (http://www.primegrid.com/forum_thread.php?id=6500)