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 A385382 #5 Jun 29 2025 11:07:25 %S A385382 1,5,28,801,129550 %N A385382 Number of polyominoes, i.e., connected nonempty subsets of square cells (or vertices), of the n X n flat torus, up to cyclic shifts and reflections of rows and columns. %H A385382 Pontus von Brömssen, <a href="/A385381/a385381.png">Illustration for n = 3</a>. %Y A385382 Main diagonal of A385381. %Y A385382 Row sums of A385383. %Y A385382 Cf. A385384 (interchange of rows and columns of the torus allowed), A385387 (edge subsets). %K A385382 nonn,more %O A385382 1,2 %A A385382 _Pontus von Brömssen_, Jun 27 2025