Woodall Primes: Definition and Status

News Flash!

On December 21, 2007, Matthew Thompson, participating in the PrimeGrid project, found the largest known Woodall prime, the first mega-digit Woodall, 3752948*2^3752948-1

News Flash!

On August 13, 2007, Stephen Kohlman, participating in the PrimeGrid project, found the largest known Woodall prime, 2367906*2^2367906-1

News Flash!

On August 4, 2007, Lasse Mejling Andersen, participating in the PrimeGrid project, found the largest known Woodall prime, 2013992*2^2013992-1

Woodall Primes are Woodall numbers that are prime and of the form Wn = n · 2n − 1.

Wn is prime 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, 667071, 1195203, 1268979, 1467763, 2013992, 2367906, 3752948 and for no other n < 11,000,000. Chris Caldwell maintains the top 20 Woodall Page.

A list of contributors to the Woodall project is here.

PrimeGrid is coordinating a distributed search for Woodall primes using BOINC.

To search for Woodall Primes of other bases, check out Steven Harvey's Generalized Woodall Search

Cullen numbers (Cn = n · 2n + 1) are related to Woodall numbers. Check here for the Cullen prime search.


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If you have any questions about the Woodall Search, you can e-mail Mark Rodenkirch or Ray Ballinger

URL: http://www.prothsearch.net/woodall.html
Last Modified: March 19, 2013