PrimeGrid
Projects
As of September 2017, PrimeGrid is working on or has worked on the following projects:

PrimeGrid

Section Title: Projects
Table Section Text: As of September 2017, PrimeGrid is working on or has worked on the following projects:

Project	Active sieve project?	Active LLR project?	Start	End	Best result

321 Prime Search (primes of the form 3×2n±1)	No	Yes	30 June 2008	Ongoing	3×211895718-1, largest prime found in the 321 Prime Search project

AP26 Search (Arithmetic progression of 26 primes)	N/A	N/A	27 December 2008	12 April 2010	43142746595714191 + 23681770×23#×n, n = 0...25 (AP26)

AP27 Search (Arithmetic progression of 27 primes)	N/A	N/A	20 September 2016	Ongoing	N/A

Generalized Fermat Prime Search (active: n = 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304 inactive: n = 8192, 16384)	Yes (manual sieving)	N/A	January 2012	Ongoing	9194441048576+1, largest known Generalized Fermat prime

Cullen Prime Search	No	Yes	August 2007	Ongoing	6679881×26679881+1, largest known Cullen prime

Message7	No	N/A	12 June 2005	August 2005	PerlBOINC testing successful

Prime Sierpinski Problem	No	Yes	10 July 2008	Ongoing	N/A

Extended Sierpinski Problem	No	Yes	7 June 2014	Ongoing	161041×27107964+1, largest and only prime found in the Extended Sierpinski Problem

PrimeGen	No	N/A	March 2006	February 2008	N/A

Proth Prime Search	Yes	Yes	29 February 2008	Ongoing	7×25775996+1

Riesel Problem	No	Yes	March 2010	Ongoing	502573×27181987-1, largest prime found in the Riesel problem

RSA-640	No	N/A	August 2005	November 2005	N/A

RSA-768	No	N/A	November 2005	March 2006	N/A

Seventeen or Bust	No	Yes	31 January 2010	Ongoing	10223 ×2 31172165+1

Sierpinski/Riesel Base 5 Problem	No	Yes	14 June 2013	Ongoing	301562×52408646−1, largest prime found in the Sierpinski/Riesel Base 5 Problem

Sophie Germain Prime Search	No	Yes	16 August 2009	Ongoing	2618163402417×21290000-1 (2p-1 = 2618163402417×21290001-1), the world record Sophie Germain prime

Twin prime Search	No	N/A	26 November 2006	25 July 2009	65516468355×2333333±1

Woodall Prime Search	No	Yes	July 2007	Ongoing	3752948×23752948−1, largest known Woodall prime

Generalized Cullen/Woodall Prime Search	Yes	Yes	22 October 2016	Ongoing	N/A

Sentence(s)

In PrimeGrid, the largest prime is 3752948 × 2³⁷⁵²⁹⁴⁸ − 1 discovered by Woodall Prime Search.

final_sentence: In PrimeGrid, the largest prime is 3752948 × 2³⁷⁵²⁹⁴⁸ − 1 discovered by Woodall Prime Search.