A Woodall prime is a Woodall number W_n = 2^n n - 1 that is prime. The first few Woodall primes are 7, 23, 383, 32212254719, 2833419889721787128217599, ... (OEIS A050918), corresponding to n = 2, 3, 6, 30, 75, 81, 115, 123, 249, 362, 384, 462, 512, 751, 822, 5312, 7755, 9531, 12379, ... (OEIS A002234). The following table summarizes large known Woodall primes. As of Mar. 2018, all n<16838832 have been checked (PrimeGrid).

integer sequence primes | Mersenne prime | Woodall number

Allan Joseph Champneys Cunningham | H. J. Woodall