A038067 Product_{k>=1} (1 + x^k)^a(k) = 1 + 2x.

2, -1, 2, -4, 6, -9, 18, -34, 56, -99, 186, -344, 630, -1161, 2182, -4114, 7710, -14532, 27594, -52476, 99858, -190557, 364722, -699214, 1342176, -2580795, 4971008, -9587556, 18512790, -35790267, 69273666, -134219794, 260300986

Offset: 1

Author

Christian G. Bower, Jan 04 1999

Keywords

• sign

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..3000
• Laura Pierson, A power sum expansion for the Kromatic symmetric function, arXiv:2408.01395 [math.CO], 2024. See p. 5.
• N. J. A. Sloane, Weigh transform

Crossrefs

Cf. A038063-A038070, A306156.

Formula

Dirichlet convolution of A038063 with characteristic function of powers of 2.

a(n) = (1/n) * (-(-2)^n + Sum_{dVladeta Jovovic, Sep 06 2002