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Number of irregular primes less than or equal to the m-th prime, where m = floor(exp(n)).
2

%I #8 Mar 05 2019 08:57:15

%S 0,0,3,9,58,160,440,1166,3202,8656,23475,64194,174557,473592,1286383,

%T 3495241,9501807,25833916

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

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

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

%Y Cf. A055739, A105457, A105461.

%K hard,nonn,more

%O 1,3

%A _Robert G. Wilson v_, Apr 07 2005

%E Definition clarified by _N. J. A. Sloane_, Jan 19 2009

%E Data corrected and a(11)-a(18) added by _Amiram Eldar_, Mar 05 2019