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

0,3

Links

Table of n, a(n) for n=0..17.

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

Sequence in context: A229673 A266091 A135255 * A330804 A335390 A075475

Adjacent sequences: A182486 A182487 A182488 * A182490 A182491 A182492

Keyword

nonn

Author

Paul D. Hanna, May 02 2012

Status

approved