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 A291929 #13 Sep 06 2017 11:05:11 %S A291929 1,0,1,0,2,0,4,1,0,9,2,0,20,6,0,46,13,1,0,105,32,2,0,242,73,6,0,557, %T A291929 171,15,0,1285,394,36,1,0,2964,914,85,2,0,6842,2109,201,6,0,15793, %U A291929 4877,467,15,0,36463,11261,1086,38,0,84187,26014,2517,89,1,0,194388 %N A291929 Triangle read by rows: T(n,k) = T(n-k,k-1) + 2*T(n-k,k) + T(n-k,k+1) with T(0,0) = 1 for 0 <= k <= A003056(n). %H A291929 Seiichi Manyama, <a href="/A291929/b291929.txt">Rows n = 0..481, flattened</a> %e A291929 First few rows are: %e A291929 1; %e A291929 0, 1; %e A291929 0, 2; %e A291929 0, 4, 1; %e A291929 0, 9, 2; %e A291929 0, 20, 6; %e A291929 0, 46, 13, 1; %e A291929 0, 105, 32, 2; %e A291929 0, 242, 73, 6; %e A291929 0, 557, 171, 15; %e A291929 0, 1285, 394, 36, 1. %Y A291929 Row sums give A291930. %Y A291929 Columns 0-1 give A000007, A006958 (for n>0). %Y A291929 Cf. A008289, A291895. %K A291929 nonn,tabf %O A291929 0,5 %A A291929 _Seiichi Manyama_, Sep 06 2017