%I #24 Oct 09 2020 03:49:03
%S 0,3,11,47,210,985,4821,24427,126726,669432,3588148,19453038,
%T 106460872,587176205,3259873268,18200088376,102107048666,575281018454,
%U 3253321522134,18459252891532,105048100696856,599403542263094,3428437672359713,19652744592040804,112879982373565581,649538196329702877,3743885544339750283,21612949469350359942,124947894360104092955
%N Number of primes < 6^n.
%H David Baugh, <a href="/A055731/b055731.txt">Table of n, a(n) for n = 0..33</a> (terms n = 29..33 found using Kim Walisch's primecount program)
%H <a href="/index/Pri#primepop">Index entries for sequences related to numbers of primes in various ranges</a>
%F a(n) = A000720(A000400(n)). - _Michel Marcus_, Oct 05 2020
%t Table[PrimePi[6^n], {n, 0, 17}]
%o (PARI) a(n) = primepi(6^n); \\ _Michel Marcus_, Oct 05 2020
%Y Cf. A006880, A007053 and A040014.
%Y Cf. A000400, A000720.
%K nonn
%O 0,2
%A _Robert G. Wilson v_, Jun 09 2000
%E a(18)-a(24) from _Henri Lifchitz_, Nov 11 2012
%E a(25)-a(28) from _Henri Lifchitz_, Aug 25 2014