Irregular primes: p is regular if and only if the numerators of the Bernoulli numbers B_2, B_4, ..., B_{p-3} (A000367) are not divisible by p.
37, 59, 67, 101, 103, 131, 149, 157, 233, 257, 263, 271, 283, 293, 307, 311, 347, 353
1 seqfan posts
Mon Jun 25 09:27:11 CEST 2012 [seqfan] A sequence characterizing the irregular primes, A000928.