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 A366003 #13 Mar 04 2025 11:11:10 %S A366003 1,2,24,359,7882,194076 %N A366003 Number of free polyominoids with n cells, allowing right-angled corner-connections and right-angled edge-connections. %C A366003 See A365995 for further details and a table of related sequences. %H A366003 Pontus von Brömssen, <a href="/A366003/a366003.svg">Illustration for sizes 1..3</a>. %H A366003 Wikipedia, <a href="https://en.wikipedia.org/wiki/Polyominoid">Polyominoid</a>. %H A366003 <a href="/index/Pol#polyominoes">Index entries for sequences related to polyominoes</a>. %Y A366003 Cf. A365995, A366004 (fixed). %Y A366003 25th row of A366766. %K A366003 nonn,hard,more %O A366003 1,2 %A A366003 _Pontus von Brömssen_, Sep 28 2023 %E A366003 a(6) from _Pontus von Brömssen_, Mar 04 2025