OFFSET
0,3
EXAMPLE
G.f.: A(x) = 1 + x + 3*x^2 + 15*x^3 + 127*x^4 + 1695*x^5 + 35199*x^6 +...
such that
A(x) = 1 + x/(1-2*x) + x^2/((1-2*x)*(1-2*2^2*x)) + x^3/((1-2*x)*(1-2*2^2*x)*(1-3*2^3*x)) +...
PROG
(PARI) {a(n)=polcoeff(sum(m=0, n, x^m/prod(k=0, m, 1-k*2^k*x+x*O(x^n))), n)}
for(n=0, 20, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, May 02 2012
STATUS
approved