**Definition.**
Woodall Primes are prime numbers that may be expressed in the form
*W*_{n} = *n* · 2^{n} − 1, *n* ≥ 2.

The original Definition and Status page was set up in early 1998 by Ray Ballinger, as part of a more general
Proth Search Project devoted to the coordinated search for primes mainly of the forms
*k* · 2^{n} + 1 or *k* · 2^{n} − 1 by using Yves Gallot's new program
`Proth.exe`. The particular Woodall Project was later administrated by Mark Rodenkirch, who finally
organized a smooth transition to
PrimeGrid's Woodall Prime Search (WOO). As a nostalgic reminiscence we
here reproduce the original page in its frozen state at a late concluding point in 2013.

The complete results and current status of the search are summarized in the following table. Cunningham and Woodall had indeed factorized all numbers
*W*_{n} for *n* ≤ 29, but could not decide about *W*_{30}. Some of the primes *W*_{n}
had been discovered (and published) in a different context. Thus, *W*_{362} first appeared as 181 · 2^{363} − 1,
*W*_{362} as 3 · 2^{391} − 1, and *W*_{512} turned out to be the 13th Mersenne prime
*M*_{521} = 2^{521} − 1.

n | Discoverer | Date |

2 | A. J. C. Cunningham & H. J. Woodall | 1917 |

3 | A. J. C. Cunningham & H. J. Woodall | 1917 |

6 | A. J. C. Cunningham & H. J. Woodall | 1917 |

2 ≤ n ≤ 29 | 1917 | |

30 | Hans Riesel | 1968 |

75 | Hans Riesel | 1968 |

81 | Hans Riesel | 1968 |

30 ≤ n ≤ 110 | 1968 | |

115 | H. C. Williams & C. R. Zarnke | 1967 |

123 | Wilfrid Keller | 1984 |

249 | Wilfrid Keller | 1984 |

362 | Ingemar Jönsson | 1972 |

384 | Hans Riesel | 1968 |

462 | Wilfrid Keller | 1984 |

512 | R. M. Robinson | 30 Jan 1952 |

751 | Wilfrid Keller | 1984 |

822 | Wilfrid Keller | 1984 |

5312 | Wilfrid Keller | 1984 |

7755 | Wilfrid Keller | 1984 |

9531 | Wilfrid Keller | 1984 |

12379 | Wilfrid Keller | 1984 |

110 < n ≤ 15000 | 1984 | |

15822 | Wilfrid Keller | 1987 |

18885 | Wilfrid Keller | 1987 |

15000 < n ≤ 20000 | 1987 | |

22971 | Jeff Young | 1997 |

23005 | Jeff Young | 1997 |

98726 | Jeff Young | 1997 |

20000 < n ≤ 100000 | 1997 | |

143018 | Ray Ballinger & ProthSearch | 25 Apr 1998 |

151023 | Kevin O'Hare & ProthSearch | 01 May 1998 |

667071 | Manfred Toplic & ProthSearch | 25 Sep 2000 |

1195203 | Mark Rodenkirch & ProthSearch | 11 Jul 2005 |

1268979 | Willem Siemelink & ProthSearch | 25 Jan 2007 |

100000 < n ≤ 1280000 | 2007 | |

1467763 | Willem Siemelink & PrimeGrid | 07 Jun 2007 |

2013992 | Lasse Mejling Andersen & PrimeGrid | 09 Aug 2007 |

2367906 | Stephen Kohlman & PrimeGrid | 03 Sep 2007 |

3752948 | Matthew J. Thompson & PrimeGrid | 27 Dec 2007 |

1280000 < n ≤ 11000000 | Mar 2013 | |

17016602 | Diego Bertolotti & PrimeGrid | 21 Mar 2018 |

11000000 < n ≤ 23521000 | Jan 2024 |