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 A151540 #13 Mar 23 2025 07:04:32 %S A151540 1,3,14,54,239,1007,4375,18728,80572,344651,1473402,6280556,26732173, %T A151540 113570050,481832209,2041461824,8639576140,36524803606,154269617690, %U A151540 651036955831,2745359144355 %N A151540 Number of 1-sided triangular strip polyedges with n cells. %H A151540 Ed Pegg, Jr., <a href="http://demonstrations.wolfram.com/PolyformExplorer/">Illustrations of polyforms</a> %H A151540 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Polyedge.html">Polyedge</a> %Y A151540 Cf. A151539, A151541, A159867. %K A151540 nonn,hard,more %O A151540 1,2 %A A151540 _Ed Pegg Jr_, May 13 2009 %E A151540 a(9)-a(13) from _Joseph Myers_, Oct 05 2011 %E A151540 a(14)-a(21) from _Bert Dobbelaere_, Mar 23 2025