Joe O

11-01-2007, 08:41 AM

PrimeGrid: 5 sub-projects all surrounding Prime number discovery.

Twin Prime Search

searches for record twin primes

Cullen Prime Search

Cullen Numbers are positive integers of the form Cn = n * 2^n + 1, where n is also a positive integer greater than zero. It has been shown that almost all Cullen numbers are composite - prime Cullen Numbers are very rare. Only fourteen Cullen Primes are known to exist and they are when n = 1, 141, 4713, 5795, 6611, 18496, 32292, 32469, 59656, 90825, 262419, 361275, 481899, and 1354828, and composite for all smaller n. It is conjectured but not yet proven that there are an infinite number of Cullen Primes and it is also unknown whether or not n and Cn can be simultaneously prime.

Woodall Prime Search

Woodall Numbers are positive integers of the form Wn = n * 2^n - 1, where n is also a positive integer greater than zero. It is conjectured that there are infinitely many such primes. The Woodall numbers Wn are primes for n=2, 3, 6, 30, 75, 81, 115, 123, 249, 362, 384, 462, 512, 751, 822, 5312, 7755, 9531, 12379, 15822, 18885, 22971, 23005, 98726, 143018, 151023, 22971, ... 2013992, 2367906 and composite for all other n less than 2,367,906.

GCW Sieve

A combined sieve in support of the Cullen and Woodal prime searches.

PSP Sieve

Combined sieve support for the Prime Sierpinski Project and the 17 or Bust Project

OS Support

There are Windows, Windows 64 bit, Linux 32 bit, and Linux 64 bit clients for most of these subprojects. See PrimeGrid Applications (http://www.primegrid.com/apps.php) for current details. If you are running 64 bit Linux and have the 32 bit libraries installed, then the 32 bit Linux binaries should work for you until the 64 bit Linux binaries are available.

Twin Prime Search

searches for record twin primes

Cullen Prime Search

Cullen Numbers are positive integers of the form Cn = n * 2^n + 1, where n is also a positive integer greater than zero. It has been shown that almost all Cullen numbers are composite - prime Cullen Numbers are very rare. Only fourteen Cullen Primes are known to exist and they are when n = 1, 141, 4713, 5795, 6611, 18496, 32292, 32469, 59656, 90825, 262419, 361275, 481899, and 1354828, and composite for all smaller n. It is conjectured but not yet proven that there are an infinite number of Cullen Primes and it is also unknown whether or not n and Cn can be simultaneously prime.

Woodall Prime Search

Woodall Numbers are positive integers of the form Wn = n * 2^n - 1, where n is also a positive integer greater than zero. It is conjectured that there are infinitely many such primes. The Woodall numbers Wn are primes for n=2, 3, 6, 30, 75, 81, 115, 123, 249, 362, 384, 462, 512, 751, 822, 5312, 7755, 9531, 12379, 15822, 18885, 22971, 23005, 98726, 143018, 151023, 22971, ... 2013992, 2367906 and composite for all other n less than 2,367,906.

GCW Sieve

A combined sieve in support of the Cullen and Woodal prime searches.

PSP Sieve

Combined sieve support for the Prime Sierpinski Project and the 17 or Bust Project

OS Support

There are Windows, Windows 64 bit, Linux 32 bit, and Linux 64 bit clients for most of these subprojects. See PrimeGrid Applications (http://www.primegrid.com/apps.php) for current details. If you are running 64 bit Linux and have the 32 bit libraries installed, then the 32 bit Linux binaries should work for you until the 64 bit Linux binaries are available.