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 A030734 #10 Feb 12 2021 18:05:14 %S A030734 4,9,20,26,29,39,40,54,66,69,83,86,102,105,122,125,144,147,171,191, %T A030734 198,221,222,224,228,263,289,292,293,298,301,333,339,342,383,386,424, %U A030734 429,432,475,478,481,530,533,570,580,588,591,635 %N A030734 Numbers k such that A030727(k) = 2. %Y A030734 Cf. A030727. %K A030734 nonn %O A030734 1,1 %A A030734 _Clark Kimberling_