From SeventeenOrBust

SeventeenOrBust is a DistributedComputing project working on a problem in NumberTheory called the SierpinskiProblem. More technical and historical information about the project can be found at the SeventeenOrBust web site, http://www.seventeenorbust.com/ and forum http://www.free-dc.org/forum/forumdisplay.php?s=&forumid=38.

SeventeenOrBust has a Seventeen Or Bust wiki. Hopefully you already know this, because you're looking at it right now.

How we are attacking the problem

The aim of the project is to find primes of the form k * 2ⁿ + 1, where k is one of the remaining 17 (now 6) candidates for Sierpinski numbers smaller than 78557, and n a positive integer. In order to find such a prime, we have a long queue of candidates, and we are running primality tests called PRP (PRobable Prime), which take a very long time, for every candidate in the queue. Because PRP takes so much computational power, we try to eliminate as many non-prime numbers as possible from the queue by Sieving, which means to take a (relatively) small integer and check whether it is a factor of one of the tests we are going to run. If there is a factor, the number is not prime and thus doesn't need to be tested. Finally, before running a particular test, one can make a last effort to find a factor for the particular k,n-pair in a few hours before running a test which will take several weeks. This is called Factoring.

Results

As of October 2007, SeventeenOrBust has discovered ten huge prime numbers (see PrimesDiscovered). The latest and largest discovery ranks as the seventh largest prime ever discovered, and it is the largest prime that is not a MersennePrime. Six of the ten primes rest in the Top 100. Check out ChrisCaldwell's PrimePages, or our page on the SierpinskiProblem, for more information.

Credits

The project was originally a collaboration between long-time friends LouieHelm and DavidNorris. The first public version of the software was released on April 1, 2002. Since then, many, many people have contributed in various ways to the project. MikeGarrison is our system administrator and does a great job taking care of the machines our server runs on. PhilChapman, FritzRedeker and MattEdson have donated a lot of hardware and currently provide for our Internet hosting. GeorgeWoltman contributed the hand-tuned assembly code that makes our software so fast. Many others have contributed mathematical, logistical and practical insight, suggestions, and moral support.