OFFSET
1,3
COMMENTS
Limit_{n->inf.} a(n)/e^n = 1-e^(-1/2).
MATHEMATICA
ip={ the list of irregular primes to 12 million }; Table[ Length[ Select[ip, # < Prime[Floor[E^n]] &]], {n, 10}]
CROSSREFS
KEYWORD
hard,nonn,more
AUTHOR
Robert G. Wilson v, Apr 07 2005
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
STATUS
approved