1,2

Conjecture: sequence is injective (all terms of this sequence occur exactly once).

Jaroslav Krizek, Table of n, a(n) for n = 1..100

a(n) = sum_(d|n) (A007955(n) / d).

a(p) = p + 1 for prime p.

The divisors of 6 are 1, 2, 3, 6. A007955(6) = product_(d|6) d = 1*2*3*6 = 36.

a(6) = 36/1 + 36/2 + 36/3 + 36/6 = 36 + 18 + 12 + 6 = 72.

Cf. A007955 (product of divisors of n.).

Sequence in context: A216868 A082732 A307893 * A009286 A076663 A277933

Adjacent sequences: A220843 A220844 A220845 * A220847 A220848 A220849

nonn

Jaroslav Krizek, Dec 22 2012

approved