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 A091181 #8 Aug 06 2021 07:06:11 %S A091181 4,6,8,11,12,19,29,31,34,37,42,46,47,63,68,75,80,93,95,100,105,106, %T A091181 115,133,136,138,141,145,151,157,159,167,169,175,187,197,210,211,217, %U A091181 221,222,232,233,247,257,263,274,275,279,306,308,327,335,337,339,355,365 %N A091181 A091180 indexed by A000040. %F A091181 a(n) = k such that A000040(k) = A091180(n). %F A091181 a(n) = A000720(A091180(n)). - _Michel Marcus_, Aug 06 2021 %Y A091181 Cf. A088878, A091179, A091180. %K A091181 nonn,easy %O A091181 1,1 %A A091181 _Ray Chandler_, Dec 27 2003 %E A091181 Offset changed to 1 by _Jinyuan Wang_, Aug 06 2021