A182489 G.f.: Sum_{n>=0} x^n / Product_{k=1..n} (1 - k*2^k*x).

1, 1, 3, 15, 127, 1695, 35199, 1114303, 53230271, 3806172863, 404501151935, 63629782432959, 14743655706528959, 5018867716910902463, 2501521070328547822783, 1821950518454974100737215, 1934522846425767844573547711, 2989550430024658138034762353855

Offset: 0

Author

Paul D. Hanna, May 02 2012

Keywords

• nonn

Examples

			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)) +...
		

Programs

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),", "))