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 A131249 #4 Feb 18 2022 22:37:22 %S A131249 1,2,1,4,4,1,8,12,5,1,16,32,18,6,1,32,80,57,24,7,1,64,192,168,82,31,8, %T A131249 1,128,448,471,260,113,39,9,1,256,1024,1270,790,374,152,48,10,1 %N A131249 A007318 * A052509. %C A131249 Row sums = A061667: (1, 3, 9, 26, 73, 201, ...). %F A131249 Binomial transform of A052509. %e A131249 First few rows of the triangle: %e A131249 1; %e A131249 2, 1; %e A131249 4, 4, 1; %e A131249 8, 12, 5, 1; %e A131249 16, 32, 18, 6, 1; %e A131249 32, 80, 57, 24, 7, 1; %e A131249 ... %Y A131249 Cf. A061667, A007318, A052509. %K A131249 nonn,tabl %O A131249 0,2 %A A131249 _Gary W. Adamson_, Jun 23 2007