A086682 Number of primes < 9^n.

0, 4, 22, 129, 847, 5968, 43934, 334349, 2607165, 20700806, 166677978, 1357200840, 11152818693, 92349038518, 769616513836, 6449247674296, 54301968156067, 459127968423610, 3896275288090795, 33173029388942512, 283263365236063678, 2425147728864084536, 20812271380294281933, 178994690348530706578, 1542475966907198337529

Offset

0,2

Links

Table of n, a(n) for n=0..24.

Formula

a(n) = A055729(2n). - R. J. Mathar, Sep 15 2012

Mathematica

Table[PrimePi[9^n], {n, 0, 14}] (* Michael De Vlieger, Mar 17 2015 *)

Prog

(Magma) [#PrimesUpTo(9^n): n in [0..9] ]; // Vincenzo Librandi, Mar 17 2015
(Sage) [prime_pi(n) for n in (1..14)] # Bruno Berselli, Mar 17 2015

Crossrefs

Cf. A000720.

Sequence in context: A100525 A199033 A370695 * A261399 A155862 A088536

Adjacent sequences: A086679 A086680 A086681 * A086683 A086684 A086685

Keyword

nonn

Author

Cino Hilliard, Jul 28 2003

Extensions

a(11)-a(24) added by David Baugh, Mar 17 2015

Status

approved