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 A209935 #6 Mar 30 2012 18:37:38
%S A209935 1,1,5,66,1735,77587,5339632,527780778,71236904519,12635518401687,
%T A209935 2857729962091681,804340796768258860,276170316701087964628,
%U A209935 113757566198465278521124,55424247710747076665462268,31554099393732823158673973698
%N A209935 G.f.: 1 = Sum_{n>=0} a(n)*x^n*Product_{k=1..n+1} (1-k^2*x) for n>0 with a(0)=1.
%e A209935 G.f.: 1 = 1*(1-x) + 1*x*(1-x)*(1-2^2*x) + 5*x^2*(1-x)*(1-2^2*x)*(1-3^2*x) + 66*x^3*(1-x)*(1-2^2*x)*(1-3^2*x)*(1-4^2*x) + 1735*x^4*(1-x)*(1-2^2*x)*(1-3^2*x)*(1-4^2*x)*(1-5^2*x) +...
%o A209935 (PARI) {a(n)=if(n==0, 1, polcoeff(1-sum(k=0, n-1, a(k)*x^k*prod(j=1, k+1, 1-j^2*x+x*O(x^n))), n))}
%o A209935 for(n=0,20,print1(a(n),", "))
%Y A209935 Cf. A082161.
%K A209935 nonn
%O A209935 0,3
%A A209935 _Paul D. Hanna_, Mar 15 2012