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 A136579 #6 Mar 27 2022 19:08:14 %S A136579 1,0,1,1,0,2,0,1,0,6,1,0,2,0,24,0,1,0,6,0,120,1,0,2,0,24,0,720,0,1,0, %T A136579 6,0,120,0,5040,1,0,2,0,24,0,720,0,40320 %N A136579 Triangle read by rows: A128174 * A136572. %C A136579 Row sums = A136580: 1, 1, 3, 7, 27, 127, ... %F A136579 A128174 * A136572 Triangle, even rows = even n! interspersed with zeros. Odd n rows, = odd n! interspersed with zeros. %F A136579 T(2*i,2*k) = (2*k)! = A010050(k). T(2*i+1,2*k+1) = (2*k+1)! = A009445(k). - _R. J. Mathar_, Jun 04 2021 %e A136579 First few rows of the triangle: %e A136579 1; %e A136579 0, 1; %e A136579 1, 0, 2; %e A136579 0, 1, 0, 6; %e A136579 1, 0, 2, 0, 24; %e A136579 0, 1, 0, 6, 0, 120; %e A136579 1, 0, 2, 0, 24, 0, 720; %e A136579 ... %Y A136579 Cf. A136580, A128174, A136572, A000142. %K A136579 nonn,easy,tabl %O A136579 0,6 %A A136579 _Gary W. Adamson_, Jan 09 2008