Seventeen or Bust Logo

Log In
About Us

Project Stats
User Stats
Team Stats

Sign Up
F.A.Q. / Wiki

Support our host!

Seventeen or Bust Distributed Computing

Latest News

(posted by Louie Helm)
Friday, 22 Nov 2013

The Mathbook by Cliff Pickover

What do Newcomb's Problem, Sierpiński Numbers, and Chaos Theory have in common? According to "The Math Book", they are each one of history's 250 major milestones in mathematics.

The Math Book notes for Sierpiński Numbers that, "As of February 2008, there were a mere six candidate numbers that had not been eliminated."

"If mathematicians are able to find a prime of the proper form for all the remaining k, the Sierpiński problem will be solved and the [over] 50-year quest ended."

So how can we hasten the end of our quest? I suggest people start crunching SB really hard again -- for at least the next couple months. Why? Because now is a "lucky" time! No, really! This is historically the luckiest season for SB finding primes:

  • 64% of the primes found by SB have been found between Thanksgiving and New Years, including the first 7!

BONUS: I currently have 6 copies of "The Math Book" and will be mailing a signed copy to every discoverer of the next 6 primes. So get crunching! Let's make another brilliant end of year find!

(posted by Louie Helm)
Wednesday, 16 May 2012

UPDATED Prime95 client available for SB

There's a new version of SB available thanks to even more great work by George Woltman.

Major Enhancements

  • 25% speed increase on Intel i5/i7 processors
  • Better multi-threaded performance
  • Faster FFT for Core 2 w/ 1MB L2 cache
  • Mac OS X client now GUI instead of CLI

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.

(posted by Louie Helm)
Thursday, 25 Nov 2010

UPDATED Prime95 client available for SB Thanks to more great work by George Woltman, there is now a new version of SB available for download.

Major Enhancement

  • 25-50% faster

As always, drop by the forums if you run into any trouble or have questions about the new client.

John Selfridge (1927 - 2010) has passed away
(posted by Louie Helm)
Wednesday, 03 Nov 2010

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.

(posted by Louie Helm)
Sunday, 31 Jan 2010

PrimeGridOur friends at PrimeGrid have partnered with us to help solve the Sierpinski problem! All PrimeGrid users are now able to process SB primality tests using their regular BOINC clients. So those users more comfortable using BOINC have the opportunity to contribute to SB without switching away from their preferred distributed computing software!

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!

(See all news articles)

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'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.

Sidebar Bottom