MathWorld Headline News

42nd Mersenne Prime (Probably) Discovered

By Eric W. Weisstein

February 18, 2005--Less than a year after the 41st Mersenne prime was reported (MathWorld headline news: June 1, 2004), Great Internet Mersenne Prime Search (GIMPS) project organizer George Woltman is reporting in a Feb. 18 email to the GIMPS mailing list that a new Mersenne number has been flagged as prime and reported to the project's server.

# p digits year discoverer (reference)
1 2 1 antiquity  
2 3 1 antiquity  
3 5 2 antiquity  
4 7 3 antiquity  
5 13 4 1461 Reguis 1536, Cataldi 1603
6 17 6 1588 Cataldi 1603
7 19 6 1588 Cataldi 1603
8 31 10 1750 Euler 1772
9 61 19 1883 Pervouchine 1883, Seelhoff 1886
10 89 27 1911 Powers 1911
- --- --- --- [**table abbreviated by entries 11-35**]
36 2976221 895832 1997 Spence, Woltman, GIMPS (Devlin 1997)
37 3021377 909526 1998 Clarkson, Woltman, Kurowski, GIMPS
38 6972593 2098960 1999 Hajratwala, Woltman, Kurowski, GIMPS
39 13466917 4053946 2001 Cameron, Woltman, GIMPS (Whitehouse 2001, Weisstein 2001ab)
40? 20996011 6320430 2003 Shafer, GIMPS (Weisstein 2003ab)
41? 24036583 7235733 2004 Findley, GIMPS (Weisstein 2004)
42? 25964951 7816230 2005 GIMPS
43? 30402457 9152052 2005 GIMPS

References

Caldwell, C. K. "The Largest Known Primes."
http://www.utm.edu/research/primes/largest.html

GIMPS: The Great Internet Mersenne Prime Search.
http://www.mersenne.org

GIMPS: The Great Internet Mersenne Prime Search Status.
http://www.mersenne.org/status.htm

Weisstein, E. W. "MathWorld Headline News: 40th Mersenne Prime Announced." Dec. 2, 2003.
http://mathworld.wolfram.com/news/2003-12-02/mersenne

Weisstein, E. W. "MathWorld Headline News: 41st Mersenne Prime Announced." Jun. 1, 2004.
http://mathworld.wolfram.com/news/2004-06-01/mersenne

Woltman, G. "New Mersenne Prime?!" Message to The Great Internet Mersenne Prime Search List. Feb. 18, 2005.