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 A130277 #8 Jun 05 2023 04:27:59 %S A130277 1,2,2,2,0,2,3,3,0,3,2,0,0,0,2,4,4,4,0,0,4,2,0,0,0,0,0,2,4,4,0,4,0,0, %T A130277 0,4,3,0,3,0,0,0,0,0,3,4,4,0,0,4,0,0,0,0,4,2,0,0,0,0,0,0,0,0,0,2,6,6, %U A130277 6,6,0,6,0,0,0,0,0,6,2,0,0,0,0,0,0,0,0,0,0,0,2,4,4,0,0,0,0,4,0,0,0,0,0,0,4 %N A130277 Triangle read by rows: A130209 * A051731 as infinite lower triangular matrices. %C A130277 Row sums = A035116: (1, 4, 4, 9, 4, 16, 4, 16, ...). %C A130277 Right and left borders = A000005, d(n): (1, 2, 2, 3, 2, 4, 2, ...). %e A130277 First few rows of the triangle: %e A130277 1; %e A130277 2, 2; %e A130277 2, 0, 2; %e A130277 3, 3, 0, 3; %e A130277 2, 0, 0, 0, 2; %e A130277 4, 4, 4, 0, 0, 4; %e A130277 2, 0, 0, 0, 0, 0, 2; %e A130277 4, 4, 0, 4, 0, 0, 0, 4; %e A130277 ... %Y A130277 Cf. A000005, A035116, A051731, A130209. %K A130277 nonn,tabl %O A130277 1,2 %A A130277 _Gary W. Adamson_, May 18 2007 %E A130277 a(56) corrected and more terms from _Georg Fischer_, Jun 05 2023