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 A290652 #4 Aug 08 2017 21:48:23 %S A290652 1,2,4,8,15,21,30,46,61,91,121,154,189,217,258,409,548,590,775,832, %T A290652 906,1227,1270,1570,1847,2116,2688,3607,3714,3990,4483,4502,6041,6045, %U A290652 8078,9255,9833,12136,12226,13208,14356,16964,17511,18858,18974,20476,23489 %N A290652 a(n) = PrimePi(A246033(n)) (where PrimePi = A000720). %e A290652 A246033(42) = 187477 = prime(16964), hence a(42) = 16964. %Y A290652 Cf. A000720, A246033. %K A290652 nonn %O A290652 1,2 %A A290652 _Rémy Sigrist_, Aug 08 2017