This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A086681 #28 Sep 08 2022 08:45:11
%S A086681 0,4,18,97,564,3512,23000,155611,1077871,7603553,54400028,393615806,
%T A086681 2874398515,21151907950,156661034233,1166746786182,8731188863470,
%U A086681 65612899915304,494890204904784,3745011184713964,28423094496953330,216289611853439384,1649819700464785589
%N A086681 Number of primes < 8^n.
%H A086681 David Baugh, <a href="/A086681/b086681.txt">Table of n, a(n) for n = 0..30</a> (terms m = 29..30 found using Kim Walisch's primecount program)
%F A086681 a(n) = A185192(3n). - _R. J. Mathar_, Sep 15 2012
%t A086681 PrimePi/@(8^Range[0,14]) (* _Harvey P. Dale_, Mar 13 2011 *)
%t A086681 Table[PrimePi[8^n], {n, 0, 15}] (* _Vincenzo Librandi_, Mar 26 2017 *)
%o A086681 (Magma) [#PrimesUpTo(8^n): n in [0..9]]; // _Vincenzo Librandi_, Mar 26 2017
%Y A086681 Cf. A000720, A185192.
%K A086681 nonn
%O A086681 0,2
%A A086681 _Cino Hilliard_, Jul 28 2003
%E A086681 More terms from _Harvey P. Dale_, Mar 13 2011
%E A086681 a(15)-a(16) from _Vincenzo Librandi_, Mar 26 2017
%E A086681 a(17)-a(22) from _David Baugh_, Oct 08 2020