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 A168581 #13 Feb 18 2023 09:34:06 %S A168581 1,1,2,2,3,3,4,5,5,6,7,7,8,9,10,10,11,12,12,13,14,15,16,17,17,18,18, %T A168581 19,21,22,23,23,25,25,26,27,28,29,30,30,32,32,33,33,35,37,38,38,39,40, %U A168581 40,42,43,44,45,45,46,47,47,49,51,52,52,53,55,56,58,58,59,60,61,62,63,64 %N A168581 Duplicate of A024699. %K A168581 dead %O A168581 1,3 %A A168581 _Juri-Stepan Gerasimov_, Nov 30 2009