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Latest News
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SPEEDUP: NEW SB CLIENT v27.7 AVAILABLE
(posted by Louie Helm) |
Wednesday, 16 May 2012 |
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There's a new version of SB available thanks to even more great work by George Woltman. Major Enhancements
Also, it's worth mentioning that Seventeen or Bust recently had its 10 year anniversary! Congratulations to everyone who has stuck with us over the years and continues to crunch for SB! This occasion was marked by being featured in Cliff Pickover's The Math Book as one of the "250 Milestones in the History of Mathematics". As always, drop by the forums if you run into any trouble or have questions about the new client. |
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NEW SB CLIENT v26.3 AVAILABLE
(posted by Louie Helm) |
Thursday, 25 Nov 2010 |
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Major Enhancement
As always, drop by the forums if you run into any trouble or have questions about the new client. |
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Thanks to more great work by George Woltman, there is now a |
John Selfridge (1927 - 2010) has passed away
(posted by Louie Helm) |
Wednesday, 03 Nov 2010 |
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We are saddened to report that one of our dear friends and a principal inspiration for this project, John Selfridge, recently passed away on October 31. There will be a memorial service in DeKalb, IL for friends and family on Nov 13. In 1962, John Selfridge proved that 78,557 is a Sierpinski number by showing that when k=78,557, all numbers of the form k*2^n+1 have a factor in the covering set {3, 5, 7, 13, 19, 37, 73}. Five years after, he and Sierpiński proposed (but could not prove) the conjecture that 78,557 is the smallest Sierpinski number. For the last 8 years, the Seventeen or Bust distributed computing project has worked to prove this conjecture. Now the search continues for the remaining 6 primes needed to prove it. |
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ALLIANCE FORMED BETWEEN SB AND PRIMEGRID!
(posted by Louie Helm) |
Sunday, 31 Jan 2010 |
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Jean Penné also recently completed work on a new custom build of LLR (v3.8.0) that increases the efficiency of our k*2^n+1 tests by 2-5%! Testing ranges for this sub-project will be separate for now, with PrimeGrid testing and retesting pre-chosen ranges. The test space was generated by using our sieve data to eliminate test candidates which created a new database of work especially for PrimeGrid. The first range will be n = 17M - 17.2M. In the event of a prime, there will be joint discovery credit shared between SB and PrimeGrid… and the discoverer of course! PrimeGrid will also do full double checking of this range and verification of matching residues. And FYI - As far as statistics go, the PrimeGrid test credit will be awarded as BOINC credit and tabulated separately from regular SB credit. Special thanks to Rytis Slatkevičius, Lennart Vogel, and John Blazek of PrimeGrid, and Jean Penné (LLR) for helping to make this collaboration possible! And thanks to all our dedicated volunteers who contribute to crunching SB! |
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NEW SB CLIENT v25.11 AVAILABLE
(posted by Louie Helm) |
Saturday, 25 Jul 2009 |
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Major Enhancements
If you're upgrading from the last version of SB (released in March), you should keep using your current prime.txt file. But if this is your first move to the new client, open the prime.txt file and put your username in the appropriate place. That's it. As always, drop by the forums if you run into any trouble or have questions about the new client. |
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You Could Be Famous!
If you're lucky enough to eliminate a multiplier, not only will you receive credit for the mathematical discovery, but you'll also have discovered an extremely large prime number: large enough to get your name in the annals of mathematical history! Eleven lucky participants have helped to discover some of the largest primes ever uncovered! You could be next!
What Is It?
SB (Seventeen or Bust) is a distributed computing system working on the Sierpinski problem. We utilizes the spare computational power of hundreds of computers around the world, creating a powerful network of machines working together on the problem. Anyone can participate: we provide software that installs on your computer and uses its "spare time" to help make mathematical discoveries. You won't even notice it's running, since it only uses your processor if it would otherwise be sitting unused.
The Sierpinski problem itself deals with numbers of the form N = k * 2^n + 1, for any odd k and n > 1. Numbers of this form are called Proth numbers. If, for some specific value of k, every possible choice of n results in a composite (non-prime) Proth number N, then that k is called a Sierpinski number. The Sierpinski problem itself is: "What is the smallest Sierpinski number?" (For a more rigorous mathematical discussion of the problem, see prothsearch.net's Sierpinski Problem page.)
John Selfridge proved, 45 years ago, that k = 78,557 is a Sierpinski number. Most number theorists believe that this is the smallest, but it hasn't yet been proven. In order to prove it, we have to show that every single k less than 78,557 is not a Sierpinski number, and to do that, we have to find some n that makes k * 2^n + 1 prime. When Seventeen or Bust was started, this had already been done for all but 17 values of k; hence the name of the project. After 7 years of computation, we have eliminated 11 multipliers: eleven down, six to go.
Who Are You Guys?
The project was started in March of 2002 as a collaboration between Louie Helm, at the University of Michigan, and David Norris at the University of Illinois. Countless individuals have also contributed to the project, most notably George Woltman (author of the GIMPS project), who contributed blindingly-fast squaring routines, and Michael Garrison, who maintains the project's central server. To these individuals and all the participants that has helped make this project possible, we sincerely thank you.
