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 A135830 #6 Mar 27 2022 23:29:37 %S A135830 1,0,1,2,0,1,1,3,0,1,4,1,4,0,1,4,7,1,5,0,1,9,5,11,1,6,0,1,12,16,6,16, %T A135830 1,7,0,1,22,17,27,7,22,1,8,0,1,33,38,23,43,8,29,1,9,0,1 %N A135830 A000012(signed) * A049310 * A000012. %C A135830 Row sums A010049: (1, 1, 3, 5, 10, 18, 33, ...). %C A135830 A135831 = A000012 * A000012(signed) * A049310. %F A135830 A000012(signed) * A049310 * A000012, as infinite lower triangular matrices, where A000012(signed) = (1; -1,1; 1,-1,1; ...). %e A135830 First few rows of the triangle: %e A135830 1; %e A135830 0, 1; %e A135830 2, 0, 1; %e A135830 1, 3, 0, 1; %e A135830 4, 1, 4, 0, 1; %e A135830 4, 7, 1, 5, 0, 1; %e A135830 9, 5, 11, 1, 6, 0, 1; %e A135830 12, 16, 6, 16, 1, 7, 0, 1; %e A135830 ... %Y A135830 Cf. A049310, A010049, A135831. %K A135830 nonn,tabl %O A135830 1,4 %A A135830 _Gary W. Adamson_, Nov 30 2007