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 A129564 #4 Feb 20 2022 01:22:03 %S A129564 1,1,1,0,1,1,1,1,1,1,0,1,1,1,1,0,0,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1, %T A129564 1,1,0,0,0,1,1,1,1,1,1,0,0,1,1,1,1,1,1,1,1 %N A129564 A129360 * A000012. %C A129564 Row sums = phi(2*n), A062570: (1, 2, 2, 4, 4, 4, 6, 8, 6, 8, ...). %F A129564 A129360 * A000012 as infinite lower triangular matrices. %e A129564 First few rows of the triangle: %e A129564 1; %e A129564 1, 1; %e A129564 0, 1, 1; %e A129564 1, 1, 1, 1; %e A129564 0, 1, 1, 1, 1; %e A129564 0, 0, 1, 1, 1, 1; %e A129564 0, 1, 1, 1, 1, 1, 1; %e A129564 1, 1, 1, 1, 1, 1, 1, 1; %e A129564 ... %Y A129564 Cf. A129360, A000012, A062570. %K A129564 nonn,tabl %O A129564 1,1 %A A129564 _Gary W. Adamson_, Apr 21 2007