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 A151531 #12 Feb 16 2025 08:33:09 %S A151531 1,2,3,5,7,15,24,49,91,183,356,734,1465,3017,6153,12721,26230,54575, %T A151531 113480,237296,496612,1042785,2192207,4619736,9747966,20607348 %N A151531 Number of 1-sided polypons with n cells. %C A151531 The division of a polypon into triangles is considered significant for this sequence, as for A057784. - _Joseph Myers_, Oct 02 2011 %H A151531 Ed Pegg, Jr., <a href="http://demonstrations.wolfram.com/PolyformExplorer/">Illustrations of polyforms</a> %H A151531 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Polypon.html">Polypon</a> %Y A151531 Cf. A057784, A151532, A151533. %K A151531 nonn,hard,more %O A151531 1,2 %A A151531 _Ed Pegg Jr_, May 13 2009 %E A151531 a(19)-a(26) from _Joseph Myers_, Oct 02 2011