%I #5 Mar 30 2012 18:37:28
%S 1,1,1,2,7,30,197,1770,22536,409456,10541949,387914810,20362048664,
%T 1525681168956,163330533908217,24973901010606886,5456672750531017964,
%U 1704092792275195175172,760753610853139920737328,485646261179496433286709024
%N G.f. satisfies: A(x) = Sum_{n>=0} x^n * Product_{k=1..n} A(k*x)/(1+k*x).
%e G.f.: A(x) = 1 + x + x^2 + 2*x^3 + 7*x^4 + 30*x^5 + 197*x^6 + 1770*x^7 +...
%e where
%e A(x) = 1 + x*A(x)/(1+x) + x^2*A(x)*A(2*x)/((1+x)*(1+2*x)) + x^3*A(x)*A(2*x)*A(3*x)/((1+x)*(1+2*x)*(1+3*x)) +...
%o (PARI) {a(n)=local(A=1+x);for(i=1,n,A=sum(m=0,n,x^m*prod(k=1,m,subst(A,x,k*x)/(1+k*x+x*O(x^n)))));polcoeff(A,n)}
%K nonn
%O 0,4
%A _Paul D. Hanna_, Jul 23 2011
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