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 A196993 #9 Feb 16 2025 08:33:15 %S A196993 6,9,14,24,42,77,144,276,538,1065,2136,4321,8790,17967,36890,76050, %T A196993 157380,326824,680880,1422570,2979572,6254175,13153242,27712901, %U A196993 58487796,123632910,261722022,554800719,1177553610,2502256578,5322993522 %N A196993 Number of fixed polypons with n cells (division into triangles is significant). %H A196993 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Polypon.html">Polypon</a> %Y A196993 Cf. A057784, A151531, A151532, A151533. %K A196993 nonn,hard %O A196993 1,1 %A A196993 _Joseph Myers_, Oct 08 2011 %E A196993 a(27)-a(31) from _Johann Peters_, Dec 16 2024