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 A131053 #4 Feb 21 2022 00:25:32 %S A131053 1,1,2,2,2,3,2,6,3,4,3,6,13,4,5,3,12,13,24,5,6,4,12,34,24,40,6,7,4,20, %T A131053 34,80,40,62,7,8,5,20,70,80,166,62,91,8,9 %N A131053 A000012 * A131047. %C A131053 Row sums = (2^n - 1): (1, 3, 7, 15, ...). %C A131053 Left border = A004526: (1, 1, 2, 2, 3, 3, ...). %C A131053 A131052 = A131047 * A000012. %F A131053 A000012 * A131047 as infinite lower triangular matrices. %e A131053 First few rows of the triangle: %e A131053 1; %e A131053 1, 2; %e A131053 2, 2, 3; %e A131053 2, 6, 3, 4; %e A131053 3, 6, 13, 4, 5; %e A131053 3, 12, 13, 24, 5, 6; %e A131053 4, 12, 34, 24, 40, 6, 7; %e A131053 ... %Y A131053 Cf. A131047, A000012, A131052, A004526. %K A131053 nonn,tabl %O A131053 1,3 %A A131053 _Gary W. Adamson_, Jun 12 2007