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 A137158 #2 Mar 30 2012 18:37:09
%S A137158 1,4,22,228,4749,200240,17034964,2913479848,999402129243,
%T A137158 686662003846640,944294243796543974,2598186366278914473948,
%U A137158 14300408328085246335179009,157434326611214704329370130880
%N A137158 G.f.: 1 = Sum_{n>=0} a(n)*x^n/(1+x)^(4*2^n).
%C A137158 Equals unsigned column 2 of triangle A137156.
%o A137158 (PARI) {a(n)=polcoeff(1-sum(k=0, n-1, a(k)*x^k/(1+x+x*O(x^n))^(2^(k+2)) ), n)}
%Y A137158 Cf. A137156; A001192, A137157, A137159, A137160.
%K A137158 nonn
%O A137158 0,2
%A A137158 _Paul D. Hanna_, Jan 24 2008