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 A133093 #9 Jun 13 2025 11:47:19 %S A133093 1,3,1,6,3,1,10,6,5,1,15,10,15,5,1,21,15,35,15,7,1,28,21,70,35,28,7,1, %T A133093 36,28,126,70,84,28,9,1,45,36,210,126,210,84,45,9,1,55,45,330,210,462, %U A133093 210,165,45,11,1 %N A133093 A007318 * A097806 * A133080. %C A133093 Row sums = A033484: (1, 4, 10, 22, 46, 94, ...). %F A133093 A007318 * A097806 * A133080 as infinite lower triangular matrices. %F A133093 Binomial transform of an infinite lower triangular matrix with (1,1,1,...) in the main diagonal, (2,1,2,1,...) in the subdiagonal and (1,0,1,0,...) in the subsubdiagonal. %e A133093 First few rows of the triangle: %e A133093 1; %e A133093 3, 1; %e A133093 6, 3, 1; %e A133093 10, 6, 5, 1; %e A133093 15, 10, 15, 5, 1; %e A133093 21, 15, 35, 15, 7, 1; %e A133093 28, 21, 70, 35, 28, 7, 1; %e A133093 ... %Y A133093 Cf. A133080, A097806, A033484. Duplicate of A131110. %K A133093 nonn,tabl %O A133093 1,2 %A A133093 _Gary W. Adamson_, Sep 09 2007