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 A316193 #6 Jul 03 2018 21:22:34 %S A316193 0,0,1,0,1,1,3,1,10,5 %N A316193 Number of symmetric self-avoiding polygons on honeycomb net with perimeter 2*n, not counting rotations and reflections as distinct. %C A316193 The sequence includes polygons of 2-fold, i.e., mirror or rotational, and higher (order >= 3) symmetry. %H A316193 Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/a258206.htm">Illustration of polygons of perimeter <= 20</a>. %Y A316193 Cf. A258206, A316194, A316196. %K A316193 nonn,walk,more %O A316193 1,7 %A A316193 _Hugo Pfoertner_, Jul 03 2018