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 A285874 #13 Apr 17 2022 01:01:19 %S A285874 1,20,400,8702,188473,4505624,106770421,2770746488,71151220765, %T A285874 1969755500063 %N A285874 Number of possible chess games at the end of the n-th ply starting without rooks. %C A285874 Gives the number of possible chess games where both sides start without rooks. Rooks are still allowed to appear later in the game through promotion. %C A285874 Does not include games which end in fewer than n plies. %C A285874 The total number of such games should be less than the total number of standard chess games, and it appears A285874(n) <= A048987(n) for all n. %C A285874 Initial terms computed using the Chesspresso engine. %H A285874 Bernhard Seybold, <a href="http://www.chesspresso.org/">Chesspresso</a>. %Y A285874 Cf. A048987 (standard), A285873 (no queens), A285875 (no knights), A285876 (no bishops), A285877 (no pawns), A285878 (pawns and king). %K A285874 nonn,hard,more,fini %O A285874 0,2 %A A285874 _Sean A. Irvine_, Apr 28 2017 %E A285874 a(9) from _Sean A. Irvine_, May 04 2017