A339719 Dirichlet g.f.: Product_{k>=2} 1 / (1 + k^(-s))^4.

1, -4, -4, 6, -4, 12, -4, -8, 6, 12, -4, -12, -4, 12, 12, 17, -4, -12, -4, -12, 12, 12, -4, 20, 6, 12, -8, -12, -4, -20, -4, -28, 12, 12, 12, 10, -4, 12, 12, 20, -4, -20, -4, -12, -12, 12, -4, -48, 6, -12, 12, -12, -4, 20, 12, 20, 12, 12, -4, 4, -4, 12, -12, 38, 12, -20, -4, -12, 12, -20

Offset: 1

Author

Ilya Gutkovskiy, Dec 14 2020

Keywords

• sign

Crossrefs

Cf. A022599, A316441, A339336, A339717, A339718, A339720, A339721, A339722.

Formula

a(1) = 1; a(n) = -Sum_{d|n, d < n} A339336(n/d) * a(d).

a(p^k) = A022599(k) for prime p.