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 A156643 #12 Feb 18 2023 09:34:56 %S A156643 0,0,1,0,1,1,1,1,2,0,2,2,1,2,3,0,3,2,2,3,2,1,3,2,1,4,3,2,5,3,2,5,4,2, %T A156643 3,4,2,5,4,1,5,3,3,4,4,1,6,4,3 %N A156643 Erroneous duplicate of A071635. %Y A156643 Cf. A071635. %K A156643 dead %O A156643 0,9 %A A156643 _Sidney Cadot_, Feb 18 2023