A105468 Number of irregular primes less than or equal to the 10^n-th prime.

0, 30, 392, 3935, 39400, 393737, 3933421, 39339651

Offset

1,2

Comments

Limit_{n->inf.} a(n)/10^n -> 1-e^(-1/2).

Links

Table of n, a(n) for n=1..8.

Mathematica

ip={ the list of irregular primes to 12 million }; Table[ Length[ Select[ip, # <= Prime[10^n] &]], {n, 5}]

Crossrefs

Cf. A000928, A006988, A105463.

Sequence in context: A224332 A280478 A020927 * A125442 A260913 A010835

Adjacent sequences: A105465 A105466 A105467 * A105469 A105470 A105471

Keyword

hard,nonn,more

Author

Robert G. Wilson v, Apr 07 2005

Extensions

Data corrected and a(6)-a(8) added by Amiram Eldar, Mar 05 2019

Status

approved