A076717 a(n) = -Sum_{d|n} (-n/d)^d.

1, 1, 4, -1, 6, 4, 8, -25, 37, 16, 12, -106, 14, 92, 384, -561, 18, -65, 20, -706, 2552, 1948, 24, -15658, 3151, 8048, 20440, -2570, 30, -33326, 32, -135393, 178512, 130816, 94968, -583219, 38, 523964, 1596560, -2465370, 42, -2521186, 44, -15082, 16364502, 8388124, 48, -78560082, 823593, 23888231

Offset: 1

Author

Vladeta Jovovic, Oct 27 2002

Keywords

• sign

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A055225, A308367, A321438.

Programs

PARI

a(n) = -sumdiv(n, d, (-n/d)^d); \\ Michel Marcus, Mar 22 2021

Formula

G.f.: Sum_{n>0} n*x^n/(1+n*x^n).