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 A129690 #4 Feb 20 2022 01:27:22 %S A129690 1,1,1,3,2,1,3,5,3,1,5,8,8,4,1,5,13,16,12,5,1,7,18,29,28,17,6,1,7,25, %T A129690 47,57,45,23,7,1,9,32,72,104,102,68,30,8,1,9,41,104,176,206,170,98,38, %U A129690 9,1 %N A129690 A129688 * A007318. %C A129690 Row sums = A084170: (1, 2, 6, 12, 52, 106, 426, ...). A129689 = A007318 * A129688. Left column = A109613: (1, 1, 3, 3, 5, 5, ...). %F A129690 A129688 * A007318 as infinite lower triangular matrices. %e A129690 First few rows of the triangle: %e A129690 1; %e A129690 1, 1; %e A129690 3, 2, 1; %e A129690 3, 5, 3, 1; %e A129690 5, 8, 8, 4, 1; %e A129690 5, 13, 16, 12, 5, 1; %e A129690 7, 18, 29, 28, 17, 6, 1; %e A129690 ... %Y A129690 Cf. A057711, A129689, A007318, A129688, A109613. %K A129690 nonn,tabl %O A129690 1,4 %A A129690 _Gary W. Adamson_, Apr 28 2007