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 A234599 #53 Aug 01 2021 14:53:35 %S A234599 2,1,4,10,46,204,1214,7497,50826,355334,2559074,18736327,139027092 %N A234599 Number of n-celled solid polyominoes (or free polycubes, allowing mirror-image identification) with chessboard coloring. %C A234599 Chessboard-colored polycubes, considering to be distinct two solids that cannot be mapped onto each other by any form of symmetry. %F A234599 a(n) = 2*A038119(n) for odd n. %Y A234599 Cf. A038119, A001933. %K A234599 nonn,more %O A234599 1,1 %A A234599 _John Mason_, Jan 07 2014 %E A234599 a(12)-a(13) from _John Mason_, Aug 01 2021