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 A129561 #4 Feb 20 2022 01:21:46 %S A129561 1,0,1,2,0,1,1,0,0,1,4,0,0,0,1,0,2,0,0,0,1,6,0,0,0,0,0,1,2,1,0,0,0,0, %T A129561 0,1,6,0,2,0,0,0,0,0,1,0,4,0,0,0,0,0,0,0,1 %N A129561 A054523 * A115369. %C A129561 Row sums = A026741: (1, 1, 3, 3, 2, 5, 3, 7, 4, ...). %F A129561 A054523 * A115369 as infinite lower triangular matrices. %e A129561 First few rows of the triangle: %e A129561 1; %e A129561 0, 1; %e A129561 2, 0, 1; %e A129561 1, 0, 0, 1; %e A129561 4, 0, 0, 0, 1; %e A129561 0, 2, 0, 0, 0, 1; %e A129561 6, 0, 0, 0, 0, 0, 1; %e A129561 ... %Y A129561 Cf. A054523, A115369, A026741. %K A129561 nonn,tabl %O A129561 1,4 %A A129561 _Gary W. Adamson_, Apr 20 2007