The discovery of SB's 10th prime last year was a huge breakthrough for SB. But now it has also helped prove a new mathematical theorem as well. Phil Moore and I were recently able to author and publish a journal paper in INTEGERS that establishes the Mixed Sierpinski Theorem. Huge thanks to Phil Moore for his independent verification of the prime 67607 + 2^16389 and for spearheading the effort to formally publish our research. Thanks are also in order for legendary prime researcher and co-author Payam Samidoost whose foundational work with dual primes forms the basis of our proof. And of course, none of this would be computationally feasible without GIMPS founder and co-author George Woltman.

The full paper is available here or you can retrieve it directly from INTEGERS by scrolling down to paper #A61 here.

Thanks again to all SB participants for everything you do. We really appreciate you. Have a Merry Christmas and a wonderful 2009!

33661•2^7031232+1 is prime! The double checking effort uncovered this new prime showing once again why it is so important to conduct these re-testing efforts. Most re-tests conclusively verify the original result but if the first test had even a single memory error during the computation, there's a chance a prime could have been missed. That's what likely happened here. The discoverer, Sturle Sunde is a giant in the prime searching world. He is the #2 overall contributor to SB and also the #4 all-time contributor to GIMPS!

This result was reported at 2:03PM EST on October 17th. We've checked and re-checked the primality several times and have now submitted it to The Prime Page where it currently stands as the 10th largest known prime number ever discovered [2,116,617 digits].

Sturle, a member of team Busty Seventeen from Oslo, Norway tells us that he started crunching SB 4 years ago to "give [him] a new set of work outside of GIMPS." He currently has 160 computers crunching GIMPS and another 110 crunching SB. Only 10 of his computers were running the crucial double-check work that lead to this new discovery. He manages all his computers from the University of Oslo with intelligent scripts that only utilize them when other users aren't logged in.

We've opened a thread to comment on the discovery in the forums. Our records confirm Sturle completed over 9,000 tests before finding this result so he is quite a deserving discoverer. That said, he couldn't have done it alone and neither could we. You all keep this effort going with your dedicated crunching and your contributions are what led to this latest find. Congratulations to the entire Seventeen or Bust community!

19249 * 2^13018586 + 1 is prime!!!! SB has done it again, discovering a new largest ever non-Mersenne prime. This latest result was submitted at 00:33 EST on March 26th by Konstantin Agafonov, a member of team TSC! Russia. Konstantin is from Korolev, Russia where he works as a systems administrator for a construction company.

Before joining SB, Konstantin participated in other DC projects like Find-a-Drug, where he was the 5th largest overall contributor! Konstantin says he has used up to 100 computers on SB. This particular prime was found on one of his 3GHz Pentium 4s running Windows.

To read more about the discovery, check out the official Press Release.

Thanks to all our dedicated number crunching volunteers... some of whom have been crunching for five years now! Every one of you helped make this discovery possible! Congratulations and Happy Cinco de Mayo!

4847 * 2^3321063 + 1 is prime! This is great news as k=4847 was a relatively dense series that required more tests in a given range than the average k. The prime was discovered at 10:50PM EST on October 15th by Richard Hassler, a long-time user who has been crunching SB since August 2003.

You may notice that this prime is smaller than the last few discoveries we've made (only 999744 digits [decimal expansion]). That's because this prime was uncovered by a double check. Hopefully those of us disappointed by the artificial slowdown that double checks have caused recently are pleased that it resulted in a new discovery so quickly. We're working to correct the scoring system so that these tests are worth as much per amount of computation as larger ones. Until we do, keep in mind that although the scoring has temporarily decreased, the ease of finishing a test has gone up which does improve your chances of actually finding a prime.

Congratulations to the whole SB community! These primes are rare so take a moment to appreciate all the hard work that goes into producing them. Each SB participant helped do their part to increase the bounds of human knowledge with this discovery. Be proud of your accomplishment! 9 down -- 8 to go.

SB v2.5.0 is now available for Win32 and Linux (and FreeBSD!) on the download page.

Changes: