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 A185898 #5 Mar 30 2012 18:37:26
%S A185898 1,2,8,58,516,5264,59056,712002,9091360,121741316,1697801200,
%T A185898 24533242088,365899614704,5615722652912,88482403906752,
%U A185898 1428528355241602,23595413088087220,398214274587320432,6859495185702804744
%N A185898 G.f. satisfies: x + x^2 = A(x - A(x)^2).
%F A185898 G.f.: A(x) = G(x) + G(x)^2 where
%F A185898 * G(x) = (sqrt(1 + 4*A(x)) - 1)/2;
%F A185898 * G(x) = Series_Reversion(x - A(x)^2).
%e A185898 G.f.: A(x) = x + 2*x^2 + 8*x^3 + 58*x^4 + 516*x^5 + 5264*x^6 +...
%e A185898 Related expansions.
%e A185898 x - A(x)^2 = x - x^2 - 4*x^3 - 20*x^4 - 148*x^5 - 1328*x^6 -...
%e A185898 Let G(x) equal the series reversion of x - A(x)^2, then
%e A185898 G(x) = x + x^2 + 6*x^3 + 45*x^4 + 414*x^5 + 4310*x^6 + 49068*x^7 +...
%e A185898 G(x)^2 = x^2 + 2*x^3 + 13*x^4 + 102*x^5 + 954*x^6 + 9988*x^7 +...
%o A185898 (PARI) {a(n)=local(A=x+2*x^2,B=serreverse(x*(1+x+x*O(x^n))));for(i=1,n,A=serreverse(B-subst(A,x,B)^2));polcoeff(A,n)}
%K A185898 nonn
%O A185898 1,2
%A A185898 _Paul D. Hanna_, Feb 05 2011