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 A193192 #7 Mar 30 2012 18:37:27 %S A193192 1,1,2,13,184,4725,188596,10765407,829780846,82924007284, %T A193192 10420182259194,1607406366386249,298555458341808338, %U A193192 65711158773953092780,16910051487116790543954,5030141451818448773854244,1712632076858599057432066794 %N A193192 G.f. satisfies: A(A(x)) = Sum_{n>=1} a(n)*x^n * (1+x)^(n^2), where g.f. A(x) = Sum_{n>=1} a(n)*x^n. %e A193192 G.f.: A(x) = x + x^2 + 2*x^3 + 13*x^4 + 184*x^5 + 4725*x^6 +... %e A193192 where %e A193192 A(A(x)) = x*(1+x) + x^2*(1+x)^4 + 2*x^3*(1+x)^9 + 13*x^4*(1+x)^16 + 184*x^5*(1+x)^25 + 4725*x^6*(1+x)^36 +...+ a(n)*x^n*(1+x)^(n^2) +... %e A193192 Explicitly, %e A193192 A(A(x)) = x + 2*x^2 + 6*x^3 + 37*x^4 + 468*x^5 + 11054*x^6 + 421428*x^7 +... %o A193192 (PARI) {a(n)=local(A=[1],F=x,G=x);for(i=1,n,A=concat(A,0);F=x*Ser(A); %o A193192 G=sum(m=1,#A-1,A[m]*x^m*(1+x+x*O(x^#A))^(m^2)); %o A193192 A[#A]=Vec(G)[#A]-Vec(subst(F,x,F))[#A]);if(n<1,0,A[n])} %Y A193192 Cf. A193193, A193194, A193195. %K A193192 nonn %O A193192 1,3 %A A193192 _Paul D. Hanna_, Jul 19 2011