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 A140530 #4 Mar 30 2012 18:51:58
%S A140530 1,1,1,1,2,1,2,3,3,1,3,6,6,4,1,4,11,13,10,5,1,5,18,27,24,15,6,1,6,28,
%T A140530 51,55,40,21,7,1
%N A140530 Triangle read by rows of coefficients of polynomials defined in comments lines.
%C A140530 At the same time that I introduced the polynomials P(n,x) defined by P(0,x)=1 and for n>0, P(n,x)=((-1)^n)/(n+1) + x*Sum_{ i=0..n-1 } [(((-1)^i)/(i+1))*P(n-1-i,x)] (Gazette des Mathematiciens 1992), I gave the generalization P(0,x)=u(0), P(n,x) = u(n) + x*Sum_{ i=0..n-1 } u(i)*P(n-1-i,x).
%C A140530 For u(n), n>=0, = 1 1 1 2 3 4 5 6 7 8 ... the array of coefficients of the polynomials P(n,x) is:
%C A140530 1
%C A140530 1 1
%C A140530 1 2 1
%C A140530 2 3 3 1
%C A140530 3 6 6 4 1
%C A140530 4 11 13 10 5 1
%C A140530 5 18 27 24 15 6 1
%C A140530 6 28 51 55 40 21 7 1
%C A140530 ...
%C A140530 which produces the present sequence.
%D A140530 P. Curtz, Gazette des Mathematiciens, 1992, no. 52, p. 44.
%Y A140530 A129891 gives the row sums.
%K A140530 nonn,tabl
%O A140530 0,5
%A A140530 _Paul Curtz_, Jun 04 2007
%E A140530 Edited by _N. J. A. Sloane_, Jul 05 2007