OFFSET
1,1
FORMULA
L.g.f.: A(x) = log[ Sum_{n>=0} log(1 + 2^n*x)^n/n! ].
EXAMPLE
A(x) = 2*x + 8*x^2/2 + 140*x^3/3 + 6840*x^4/4 + 988272*x^5/5 +...
A(x) = log(G(x)) where G(x) = g.f. of A014070:
G(x) = 1 + 2*x + 6*x^2 + 56*x^3 + 1820*x^4 +... + C(2^n,n)*x^n +...
PROG
(PARI) {a(n)=n*polcoeff(log(sum(k=0, n, binomial(2^k, k)*x^k)+x*O(x^n)), n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, May 02 2008
STATUS
approved