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 A151519 #23 Feb 16 2025 08:33:09 %S A151519 1,4,6,22,56,198,624,2182,7448,26319,92826,332181,1192845,4315845, %T A151519 15678200,57227380,209623109,770516966,2840466846,10499678185, %U A151519 38905008340,144475534207 %N A151519 Number of 1-sided polytans (polyaboloes) with n cells. %H A151519 Ed Pegg, Jr., <a href="http://demonstrations.wolfram.com/PolyformExplorer/">Illustrations of polyforms</a> %H A151519 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Polytan.html">Polytan</a> %Y A151519 Cf. A006074. %K A151519 nonn,hard,more %O A151519 1,2 %A A151519 _Ed Pegg Jr_, May 13 2009 %E A151519 a(13)-a(14) from _George Sicherman_, Sep 27 2012 %E A151519 a(15) from _George Sicherman_, Aug 06 2013 %E A151519 a(15) corrected and a(16)-a(20) from _John Mason_, Jan 07 2022 %E A151519 a(21)-a(22) from _Aaron N. Siegel_, Jun 07 2022