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 A139147 #5 Mar 03 2013 13:23:23
%S A139147 1,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,2,2,1,1,1,1,2,3,2,1,1,1,1,2,3,3,2,
%T A139147 1,1,1,1,2,3,5,3,2,1,1,1,1,2,3,5,5,3,2,1,1,1,1,2,3,5,8,5,3,2,1,1,1,1,
%U A139147 2,3,5,8,8,5,3,2,1,1
%N A139147 Triangle read by rows: replace A003983(n,k) with F(n).
%F A139147 Replace term A003983(n,k) with F(n).
%F A139147 Triangle T(n,k)=sum{j=0..n, [j<=k]*[j<=n-k]*(F(j+1)-F(j))}. [From _Paul Barry_, Jan 18 2009]
%e A139147 First few rows of A003983 are [1; 1,1; 1,2,1; 1,2,2,1;...] which become [F(1); F(1),F(1); F(1),F(2),F(1); F(1),F(2),F(2),F(1);...] =
%e A139147 1;
%e A139147 1, 1;
%e A139147 1, 1, 1;
%e A139147 1, 1, 1, 1;
%e A139147 1, 1, 2, 1, 1;
%e A139147 1, 1, 2, 2, 1, 1;
%e A139147 1, 1, 2, 3, 2, 1, 1;
%e A139147 1, 1, 2, 3, 3, 2, 1, 1;
%e A139147 1, 1, 2, 3, 5, 3, 2, 1, 1;
%e A139147 1, 1, 2, 3, 5, 5, 3, 2, 1, 1;
%e A139147 1, 1, 2, 3, 5, 8, 5, 3, 2, 1, 1;
%e A139147 ...
%Y A139147 Cf. A134404.
%K A139147 nonn,tabl
%O A139147 1,13
%A A139147 _Gary W. Adamson_ & Klaus Breyer, Apr 10 2008