On 21 Dec 2007, 10:09:30 UTC, PrimeGrid's Woodall Prime
Search found the 33rd and largest known to date Woodall
prime. It's the first found mega-digit prime using LLR.
The discovery was made by Matthew J. Thompson of the
United States using an Intel P4 @ 2.8 GHz with 512 MB
RAM. This computer took almost 15 hours and 11 minutes to
The prime was verified on 24 Dec 2007, 1:10:44 UTC, by an
AMD Athlon64 X2 3600+ with 2GB RAM. This computer took a
little over 24 hours 55 minutes to test.
This is PrimeGrid's third Woodall prime. Since the search
began, just over 134,000 tests have been completed by
4524 users using 9149 computers.
Using a single PC would have taken years to find this
prime. So this timely discovery would not have been
possible without the hundreds 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 Brian Rodenkirk, Lennart
Vogel, Joseph M. Osiecki, Geoffrey Reynolds, and Paul
Additional thanks to all the sievers who prepared the
work for PrimeGrid: Sievers.
PrimeGrid's Woodall Prime Search will continue to search
for even larger Woodall Primes. To join the search please
visit PrimeGrid: www.primegrid.com