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 A104731 #5 Sep 17 2013 13:21:28
%S A104731 1,1,2,1,5,3,1,5,11,4,1,5,16,19,5,1,5,16,37,29,6,1,5,16,44,71,41,7,1,
%T A104731 5,16,44,103,121,55,8,1,5,16,44,112,211,190,71,9,1,5,16,44,112,261,
%U A104731 390,281,89,10,1,5,16,44,112,272,555,666,397,109,11
%N A104731 Triangle T(n,k) = sum_{j=k..n} (j+1)*binomial(k,j-k), read by rows, 0<=k<=n.
%F A104731 Product of the triangles A(n,k) = k+1 and B = binomial(k,n-k) = [1; 0, 1; 0, 1, 1; 0, 0, 2, 1; 0, 0, 1, 3, 1;...], the triangular view of A026729.
%e A104731 The first few rows of the triangle are:
%e A104731 1;
%e A104731 1, 2;
%e A104731 1, 5, 3;
%e A104731 1, 5, 11, 4
%e A104731 1, 5, 16, 19, 5;
%e A104731 1, 5, 16, 37, 29, 6;
%e A104731 ...
%Y A104731 Cf. A014286 (row sums), A045925, A026729.
%K A104731 nonn,tabl
%O A104731 0,3
%A A104731 _Gary W. Adamson_, Mar 20 2005