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 A354587 #20 Oct 01 2022 19:41:03 %S A354587 1,3,1,7,1,3,1,15,1,3,1,7,1,3,1,31,1,3,1,7,1,3,1,15,1,3,1,49,1,3,1,63, %T A354587 1,3,1,7,1,3,1,15,1,3,1,7,1,3,1,31,1,3,1,8,1,9,1,11,1,5,1,5,1,111,1, %U A354587 127,1,3,1,7,1,3,1,15,1,3,1,21,1,3,1,31,1,3 %N A354587 Diagonal of Sprague-Grundy values for n X m 2D Toppling Dominoes L's. %C A354587 2D Toppling Dominoes is played in the same manner as conventional Toppling Dominoes, with the addition of toppling in the north and south directions. An n X m L is defined as a column of n dominoes and a row of m dominoes intersecting at an endpoint for both row and column. An n X m L comprises n+m-1 dominoes. %C A354587 It is known that alternate terms are 1. %H A354587 Ian C Haile, <a href="https://github.com/IanHaile/2D_Toppling_Dominoes">Python program</a> %Y A354587 Main diagonal of A354586 viewed as square array. %K A354587 easy,nonn %O A354587 1,2 %A A354587 _Ian C Haile_, Aug 18 2022