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 A128411 #2 Mar 30 2012 18:59:20
%S A128411 1,-2,1,4,-8,2,-8,36,-24,4,16,-128,160,-64,8,-32,400,-800,560,-160,16,
%T A128411 64,-1152,3360,-3584,1728,-384,32,-128,3136,-12544,18816,-13440,4928,
%U A128411 -896,64,256,-8192,43008,-86016,84480,-45056,13312
%N A128411 Coefficient array for orthogonal polynomials defined by C(2n,n).
%C A128411 Define {p(n,x)} to be the family of orthogonal polynomials on [0,4] for the weight function (1/pi)*1/sqrt(x(4-x)) which defines C(2n,n). We have p(n,x)=(2x-4)*p(n-1,x)-4*p(n-2,x), with p(0,x)=1, p(1,x)=-2+x. A scaled version of this triangle is given by A128412.
%F A128411 Column k has g.f. if(k=0,1/(1+2x),(1-2x)*((2^(k-1)+0^k/2)*x^k/(1+2x)^(2k+1))).
%F A128411 T(n,k)=(C(n+k,n-k)(-1)^(n-k)-C(n+k-1,n-k-1)(-1)^(n-k-1))*(2^(n-1)+0^n/2); T(n,k)=A110162(n,k)*(2^(n-1)+0^n/2); - _Paul Barry_, Mar 22 2007
%e A128411 Triangle begins
%e A128411 1,
%e A128411 -2, 1,
%e A128411 4, -8, 2,
%e A128411 -8, 36, -24, 4,
%e A128411 16, -128, 160, -64, 8,
%e A128411 -32, 400, -800, 560, -160, 16,
%e A128411 64, -1152, 3360, -3584, 1728, -384, 32
%K A128411 easy,sign,tabl
%O A128411 0,2
%A A128411 _Paul Barry_, Mar 02 2007