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 A122438 #6 Mar 14 2015 18:15:03
%S A122438 1,2,1,4,4,1,8,8,6,1,16,16,16,8,1,32,32,32,28,10,1,64,64,64,64,44,12,
%T A122438 1,128,128,128,128,120,64,14,1,256,256,256,256,256,208,88,16,1,512,
%U A122438 512,512,512,512,496,336,116,18,1,1024,1024,1024,1024,1024,1024,912,512,148
%N A122438 Riordan array (1/(1-2x), x(1+2x)).
%C A122438 Generalized Whitney triangle. Row sums are A045883(n+1). Diagonal sums are A122439.
%F A122438 Number triangle T(n,k)=sum{j=0..n-k, C(k,n-k-j)}*2^(n-k).
%e A122438 Number triangle begins
%e A122438 1,
%e A122438 2, 1,
%e A122438 4, 4, 1,
%e A122438 8, 8, 6, 1,
%e A122438 16, 16, 16, 8, 1,
%e A122438 32, 32, 32, 28, 10, 1,
%e A122438 64, 64, 64, 64, 44, 12, 1
%t A122438 T[n_, k_] := Sum[ Binomial[k, n - k - j]*2^(n - k), {j, 0, n - k}]; Table[ T[n, k], {n, 0, 10}, {k, 0, n}] // Flatten (* _Robert G. Wilson v_, Sep 14 2006 *)
%Y A122438 Cf. A004070.
%K A122438 easy,nonn,tabl
%O A122438 0,2
%A A122438 _Paul Barry_, Sep 05 2006
%E A122438 More terms from _Robert G. Wilson v_, Sep 14 2006