A105461 The floor(exp(n))-th irregular prime.

37, 59, 149, 389, 809, 2543, 8089, 25301, 76493, 232439, 695407, 2040551, 5993249, 17532407, 50970511, 147468721, 424835869, 1219642051

Offset: 1

Author

Robert G. Wilson v, Apr 07 2005

Keywords

• hard
• nonn
• more

Crossrefs

Cf. A000928, A000149, A055739, A105457, A105466.

Programs

Mathematica

ip={ the list of irregular primes to 12 million }; Table[ ip[[ Floor[E^n]]], {n, 0, 12}]

Formula

a(n) = A000928(A000149(n)). - Amiram Eldar, Mar 05 2019

Extensions

a(13) corrected and a(14)-a(18) added by Amiram Eldar, Mar 05 2019