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 A133804 #13 Jun 08 2023 09:36:44 %S A133804 1,2,1,3,3,1,4,7,4,1,5,14,10,5,1,6,25,20,16,6,1,7,41,35,41,21,7,1,8, %T A133804 63,56,91,56,29,8,1,9,92,84,182,126,92,36,9,1,10,129,120,336,252,246, %U A133804 120,46,10,1,11,175,165,582,462,582,330,175,55,11,1,12,231,220,957,792,1254,792,550,220,67,12,1 %N A133804 Triangle read by rows: A007318 * A133080 * A133566. %C A133804 Row sums = A133124: (1, 3, 7, 16, 35, 74, 153, ...). %C A133804 A133805 = binomial transform of (A133566 * A133080). %F A133804 Binomial transform of (A133080 * A133566), where A133080 * A133566 = an infinite lower triangular matrix with (1,1,1,...) in the main and subdiagonals and (0,1,0,1,0,...) in the subsubdiagonal. %e A133804 First few rows of the triangle: %e A133804 1; %e A133804 2, 1; %e A133804 3, 3, 1; %e A133804 4, 7, 4, 1; %e A133804 5, 14, 10, 5, 1; %e A133804 6, 25, 20, 16, 6, 1; %e A133804 7, 41, 35, 41, 21, 7, 1; %e A133804 ... %Y A133804 Cf. A133080, A133124, A133566. %K A133804 nonn,tabl %O A133804 1,2 %A A133804 _Gary W. Adamson_, Sep 23 2007 %E A133804 a(21) = 1 inserted and more terms from _Georg Fischer_, Jun 08 2023