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 A129340 #4 Mar 30 2012 18:51:51
%S A129340 1,2,3,6,8,11,22,28,36,47,94,116,144,180,227,454,548,664,808,988,1215,
%T A129340 2430,2884,3432,4096,4904,5892,7107,14214,16644,19528,22960,27056,
%U A129340 31960,37852,44959,89918,104132,120776,140304,163264,190320,222280
%N A129340 Triangular array read by rows: for n, k >= 1, a(n+1, 1) = 2*a(n, n); a(n+1, k+1) = a(n, k)+a(n+1, k).
%C A129340 Main diagonal is A035009. First column is A001861.
%F A129340 a(n, n) = A035009(n). For k < n, a(n, k) = 2*sum_{i = 1..k} binomial(k-1, i-1)*A035009(n-i).
%Y A129340 Cf. A001861, A035009.
%K A129340 nonn,tabl,easy
%O A129340 1,2
%A A129340 _Paul Curtz_, May 28 2007
%E A129340 Edited and extended by _David Wasserman_, May 02 2008