OFFSET
0,3
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..76
FORMULA
E.g.f. satisfies: log(A(x)) = x*A(2*x).
a(n+1) = Sum_{i=0..n} (i+1)*2^i*binomial(n,i)*a(i)*a(n-i). - Vladeta Jovovic, Dec 29 2006
a(n) ~ c * n! * 2^(n*(n-1)/2), where c = 1.972549257529822552687919986141209749606505056... . - Vaclav Kotesovec, Jul 31 2014
EXAMPLE
A(x) = 1 + 1*x + 5*x^2/2! + 73*x^3/3! + 2649*x^4/4! + 226881*x^5/5! +...
PROG
(PARI) a(n)=local(A=exp(x)); for(i=1, n, A=exp(x*(2^(n-i))*A+x*O(x^n))); n!*polcoeff(A, n)
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jun 24 2004
STATUS
approved