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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.

Joe O
11-12-2007, 08:53 AM
(November 12, 2007 11:20 EST)
PrimeGrid PSP Sieve has completed 100T and found 4036 factors.
This is just 30 days after starting this subproject.

Joe O
12-18-2007, 01:00 PM
Forgot to post this last week. After only 2 months (61 days), PG PSP Sieve had finished 275T and found 10225 factors.
They should reach 300T and 1100 factors sometime tomorrow. This will be only 67 days after starting!

Joe O
12-21-2007, 08:27 AM
Again, some old news:
2007-12-05 17:45 UTC New subproject available
PrimeGrid released the LLR application for the 321 Search. 321 is attempting to find a mega prime in the form 3*2^n-1. The 4+ year old project currently holds the largest non-GIMPS/non-Seventeen or Bust prime.
As usual, you can choose to crunch work for this project by visiting your project preferences page. Supported platforms: 32bit Linux & Windows.

:welcome: And some new news (not yet posted on PrimeGrid, but posted on the PSP forum by LTD) :
PrimeGrid has released the LLR application for the Prime Sierpinski Problem.
Supported platforms: 32bit Windows.

[XC] riptide
12-21-2007, 08:41 AM