A105466 Number of irregular primes less than or equal to the m-th prime, where m = floor(exp(n)).

0, 0, 3, 9, 58, 160, 440, 1166, 3202, 8656, 23475, 64194, 174557, 473592, 1286383, 3495241, 9501807, 25833916

Offset: 1

Author

Robert G. Wilson v, Apr 07 2005

Keywords

• hard
• nonn
• more

Comments

Limit_{n->inf.} a(n)/e^n = 1-e^(-1/2).

Crossrefs

Cf. A055739, A105457, A105461.

Programs

Mathematica

ip={ the list of irregular primes to 12 million }; Table[ Length[ Select[ip, # < Prime[Floor[E^n]] &]], {n, 10}]

Extensions

Definition clarified by N. J. A. Sloane, Jan 19 2009

Data corrected and a(11)-a(18) added by Amiram Eldar, Mar 05 2019