A038068 Product_{k>=1}(1 + x^k)^a(k) = 1 + 3x.

3, -3, 8, -21, 48, -116, 312, -831, 2184, -5880, 16104, -44336, 122640, -341484, 956576, -2690841, 7596480, -21522228, 61171656, -174342144, 498111952, -1426403748, 4093181688, -11767919276, 33891544368, -97764009000

Offset

1,1

Links

Seiichi Manyama, Table of n, a(n) for n = 1..2000

Christian G. Bower, PARI programs for transforms, 2007.

N. J. A. Sloane, Maple programs for transforms, 2001-2020.

Formula

Dirichlet convolution of A038064 with characteristic function of powers of 2.

a(n) = (1/n) * (-(-3)^n + Sum_{d<n and d|n} (-1)^(n/d) * d * a(d)). - Seiichi Manyama, Jun 23 2018

Crossrefs

Cf. A038063-A038070, A306157.

Sequence in context: A027376 A190659 A202536 * A267952 A221773 A101126

Adjacent sequences: A038065 A038066 A038067 * A038069 A038070 A038071

Keyword

sign

Author

Christian G. Bower, Jan 04 1999

Status

approved