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 A151527 #9 Feb 16 2025 08:33:09 %S A151527 1,2,3,6,12,26,57,130,297,694,1622,3810,8966,21092,49732,116952, %T A151527 275695,647788,1525610,3581170,8424478,19757082,46425561 %N A151527 Number of 2-sided strip polyrects with n cells. %H A151527 Ed Pegg, Jr., <a href="http://demonstrations.wolfram.com/PolyformExplorer/">Illustrations of polyforms</a> %H A151527 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Polyrect.html">Polyrect</a> %K A151527 nonn,hard,more %O A151527 1,2 %A A151527 _Ed Pegg Jr_, May 13 2009 %E A151527 a(15)-a(23) from _Joseph Myers_, Nov 22 2010