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 A007545 M5100 #24 Feb 16 2025 08:32:31 %S A007545 1,20,400,8902,197742,4897256,120921506,3284294545,88867026005 %N A007545 Number of chess games with n plies (another version). %C A007545 Up to a(6) this is the number of chess games with all legality constraints removed, even allowing the king to be captured. (This differs from the number of positions in suicide chess, as suicide chess contains compulsory captures.) - _Richard Bean_, Jun 18 2003 %D A007545 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A007545 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Chess.html">Chess</a> %H A007545 <a href="/index/Ch#chess">Index entries for sequences related to number of chess games</a> %Y A007545 Cf. A006494, A048987. %K A007545 fini,nonn,hard %O A007545 0,2 %A A007545 Ken Thompson (ken(AT)google.com) %E A007545 I am not sure of the precise rules that were used to compute these numbers. A006494 and A048987 are the preferred versions of this sequence. - _N. J. A. Sloane_.