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 A115292 #3 Mar 30 2012 18:59:13
%S A115292 1,4,4,7,17,7,8,32,32,8,8,39,66,39,8,8,40,88,88,40,8,8,40,95,130,95,
%T A115292 40,8,8,40,96,152,152,96,40,8,8,40,96,159,194,159,96,40,8,8,40,96,160,
%U A115292 216,216,160,96,40,8,8,40,96,160,223,258,223,160,96,40,8
%N A115292 Correlation triangle for (1+x)^3/(1-x).
%C A115292 Row sums are A115293. Diagonal sums are A115294. T(2n,n) is A115295. T(2n,n)-T(2n,n+1) is 1,10,27,35,35,35,... The transform of (-1)^n by this matrix is 1,0,-3,0,4,0,-4,0,4,...
%F A115292 G.f.: (1+x)^3*(1+xy)^3/((1-x)(1-x*y)(1-x^2*y)); Number triangle T(n, k)=sum{j=0..n, [j<=k]*A115291(k-j)*[j<=n-k]*A115291(n-k-j)}.
%e A115292 Triangle begins
%e A115292 1;
%e A115292 4, 4;
%e A115292 7, 17, 7;
%e A115292 8, 32, 32, 8;
%e A115292 8, 39, 66, 39, 8;
%e A115292 8, 40, 88, 88, 40, 8;
%e A115292 8, 40, 95, 130, 95, 40, 8;
%e A115292 8, 40, 96, 152, 152, 96, 40, 8;
%K A115292 easy,nonn,tabl
%O A115292 0,2
%A A115292 _Paul Barry_, Jan 19 2006