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 A155052 #2 Mar 30 2012 18:59:22
%S A155052 1,-1,1,1,-1,1,-1,1,-1,1,1,-1,2,-1,1,-1,1,-2,2,-1,1,1,-1,2,1,2,-1,1,
%T A155052 -1,1,-2,-1,1,2,-1,1,1,-1,2,1,8,1,2,-1,1,-1,1,-2,-1,-8,8,1,2,-1,1,1,
%U A155052 -1,2,1,8,20,8,1,2,-1,1
%N A155052 Image of symmetric Catalan based triangle A155050 under ((1+x)/(1-x),x)^{-1}.
%C A155052 Row sums are aerated Catalan numbers (A000108).
%e A155052 Triangle begins
%e A155052 1,
%e A155052 -1, 1,
%e A155052 1, -1, 1,
%e A155052 -1, 1, -1, 1,
%e A155052 1, -1, 2, -1, 1,
%e A155052 -1, 1, -2, 2, -1, 1,
%e A155052 1, -1, 2, 1, 2, -1, 1,
%e A155052 -1, 1, -2, -1, 1, 2, -1, 1,
%e A155052 1, -1, 2, 1, 8, 1, 2, -1, 1,
%e A155052 -1, 1, -2, -1, -8, 8, 1, 2, -1, 1,
%e A155052 1, -1, 2, 1, 8, 20, 8, 1, 2, -1, 1
%K A155052 sign,tabl
%O A155052 0,13
%A A155052 _Paul Barry_, Jan 19 2009