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 A117316 #5 Jan 06 2014 05:55:21
%S A117316 1,0,1,2,0,1,2,4,0,1,6,4,6,0,1,10,16,6,8,0,1,22,28,30,8,10,0,1,42,72,
%T A117316 54,48,10,12,0,1,86,148,158,88,70,12,14,0,1,170,336,342,288,130,96,14,
%U A117316 16,0,1,342,716,846,648,470,180,126,16,18,0,1
%N A117316 Riordan array ((1-x)/(1-x-2x^2),x(1-x)/(1-x-2x^2)).
%C A117316 Product of A007318 and alternating sign version of A073370. Row sums are A001333. Diagonal sums are A052973. First column is A078008. Convolution array for A078008.
%F A117316 T(n,k)=sum{j=0..n-k,sum{i=0..k+1, C(k+1,i)C(k+j,j)C(n-i-j,n-k-i-j)(-1)^(i+j)2^(n-k-i-j)}}
%F A117316 T(n,k)=T(n-1,k)+T(n-1,k-1)+2*T(n-2,k)-T(n-2,k-1), T(0,0)= 1, T(1,0)=0, T(1,1)=1, T(n,k)=0 if k<0 or if k>n. - _Philippe Deléham_, Jan 04 2013
%e A117316 Triangle begins
%e A117316 1,
%e A117316 0, 1,
%e A117316 2, 0, 1,
%e A117316 2, 4, 0, 1,
%e A117316 6, 4, 6, 0, 1,
%e A117316 10, 16, 6, 8, 0, 1,
%e A117316 22, 28, 30, 8, 10, 0, 1,
%e A117316 42, 72, 54, 48, 10, 12, 0, 1
%K A117316 easy,nonn,tabl
%O A117316 0,4
%A A117316 _Paul Barry_, Mar 07 2006