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 A193194 #9 Mar 30 2012 18:37:27
%S A193194 1,1,1,3,20,262,5367,158413,6318384,326575077,21199737973,
%T A193194 1687053244236,161418184139781,18276066372054109,2416167457088427950,
%U A193194 368773198369779785338,64348161941454274119082,12728047101293068225626576,2832615019902477894227329544
%N A193194 G.f. satisfies: A(A(x)) = Sum_{n>=1} a(n)*x^n * (1+x)^(n*(n+1)/2), where g.f. A(x) = Sum_{n>=1} a(n)*x^n.
%e A193194 G.f.: A(x) = x + x^2 + x^3 + 3*x^4 + 20*x^5 + 262*x^6 + 5367*x^7 +...
%e A193194 where
%e A193194 A(A(x)) = x*(1+x) + x^2*(1+x)^3 + x^3*(1+x)^6 + 3*x^4*(1+x)^10 + 20*x^5*(1+x)^15 + 262*x^6*(1+x)^21 +...+ a(n)*x^n*(1+x)^(n*(n+1)/2) +...
%e A193194 Explicitly,
%e A193194 A(A(x)) = x + 2*x^2 + 4*x^3 + 12*x^4 + 66*x^5 + 717*x^6 + 13344*x^7 +...
%o A193194 (PARI) {a(n)=local(A=[1],F=x,G=x);for(i=1,n,A=concat(A,0);F=x*Ser(A);
%o A193194 G=sum(m=1,#A-1,A[m]*x^m*(1+x+x*O(x^#A))^(m*(m+1)/2));
%o A193194 A[#A]=Vec(G)[#A]-Vec(subst(F,x,F))[#A]);if(n<1,0,A[n])}
%Y A193194 Cf. A193192, A193193, A193195.
%K A193194 nonn
%O A193194 1,4
%A A193194 _Paul D. Hanna_, Jul 19 2011