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 A161637 #2 Mar 30 2012 18:37:17
%S A161637 1,1,3,7,25,49,421,589,20051,109571,6897743,7158695,12593657691,
%T A161637 12622726251,80459328159219,305712703088131,2306380162670320841,
%U A161637 2307152558777717417,269444164561317686825525,269453394201317013516237
%N A161637 G.f.: A(x) = exp( Sum_{n>=1} x^n/(1 - 2^(n^2)*x^n)/n ).
%e A161637 G.f.: A(x) = 1 + x + 3*x^2 + 7*x^3 + 25*x^4 + 49*x^5 +...
%e A161637 log(A(x)) = x/(1-2*x) + x^2/(1-2^4*x^2)/2 + x^3/(1-2^9*x^3)/3 +...
%o A161637 (PARI) {a(n)=if(n==0, 1, polcoeff(exp(sum(k=1, n, x^k/(1-2^(k^2)*x^k +x*O(x^n))/k)), n))}
%Y A161637 Cf. A158097.
%K A161637 nonn
%O A161637 0,3
%A A161637 _Paul D. Hanna_, Jun 18 2009