A054601 a(n) = Sum_{d|n, d odd} d*2^(n/d - 1), a(0)=0.

0, 1, 2, 7, 8, 21, 38, 71, 128, 277, 522, 1035, 2072, 4109, 8206, 16467, 32768, 65553, 131186, 262163, 524328, 1048817, 2097174, 4194327, 8388992, 16777321, 33554458, 67109695, 134217784, 268435485, 536872638, 1073741855, 2147483648

Offset

0,3

Links

Seiichi Manyama, Table of n, a(n) for n = 0..1000

Formula

G.f.: Sum_{k>0} (1-(-1)^k)/2*k*x^k/(1-2*x^k). - Vladeta Jovovic, Oct 17 2003

Prog

(PARI) a(n) = if (n, sumdiv(n, d, if (d%2, d*2^(n/d - 1))), 0); \\ Michel Marcus, Mar 10 2021

Crossrefs

Cf. A054598, A054599, A054600, A000016, A000031.

Sequence in context: A306903 A026579 A167767 * A279847 A291629 A117558

Adjacent sequences: A054598 A054599 A054600 * A054602 A054603 A054604

Keyword

nonn

Author

N. J. A. Sloane, Apr 16 2000

Status

approved