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 A129558 #4 Feb 18 2022 22:46:41 %S A129558 1,1,1,1,0,1,2,1,0,1,3,0,0,0,1,1,1,1,0,0,1,5,0,0,0,0,0,1,4,2,0,1,0,0, %T A129558 0,1,4,0,1,0,0,0,0,0,1,3,3,0,0,1,0,0,0,0,1 %N A129558 A054523 * A129360. %C A129558 Row sums = A062570, phi(2*n): (1, 2, 2, 4, 4, 4, 6, 8, ...). %F A129558 A054523 * A129360 as infinite lower triangular matrices. %e A129558 First few rows of the triangle: %e A129558 1; %e A129558 1, 1; %e A129558 1, 0, 1; %e A129558 2, 1, 0, 1; %e A129558 3, 0, 0, 0, 1; %e A129558 1, 1, 1, 0, 0, 1; %e A129558 5, 0, 0, 0, 0, 0, 1; %e A129558 4, 2, 0, 1, 0, 0, 0, 1; %e A129558 4, 0, 1, 0, 0, 0, 0, 0, 1; %e A129558 ... %Y A129558 Cf. A054523, A129360, A062570. %K A129558 nonn,tabl %O A129558 1,7 %A A129558 _Gary W. Adamson_, Apr 20 2007