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 A130269 #4 Feb 20 2022 14:46:56 %S A130269 1,3,4,6,7,9,10,11,13,16,15,16,18,21,25,21,22,24,27,31,36,28,29,31,34, %T A130269 38,43,49,36,37,39,42,46,51,57,64,45,46,48,51,55,60,66,73,81,55,56,58, %U A130269 61,65,70,76,83,91,100 %N A130269 A002260 * A051340. %C A130269 Row sums = A002412: (1, 7, 22, 50, 95, ...). %F A130269 A002260 * A051340 as infinite lower triangular matrices. %e A130269 First few rows of the triangle: %e A130269 1; %e A130269 3, 4; %e A130269 6, 7, 9; %e A130269 10, 11, 13, 16; %e A130269 15, 16, 18, 21, 25, %e A130269 21, 22, 24, 27, 31, 36; %e A130269 28, 29, 31, 34, 38, 43, 49; %e A130269 ... %Y A130269 Cf. A002260, A051340, A002412. %K A130269 nonn,tabl %O A130269 1,2 %A A130269 _Gary W. Adamson_, May 18 2007