OFFSET
1,3
COMMENTS
Limit_{n->inf.} a(n)/3^n = 1-e^(-1/2).
MATHEMATICA
ip={ the list of irregular primes to 12 million }; Table[ Length[ Select[ip, # < Prime[3^n] &]], {n, 9}]
CROSSREFS
KEYWORD
hard,nonn,more
AUTHOR
Robert G. Wilson v, Apr 07 2005
EXTENSIONS
Terms corrected and a(10)-a(16) added by Amiram Eldar, Mar 05 2019
STATUS
approved