A079076 Numerator of Sum{n/d : 1<d<n and n mod d > 0}.

0, 0, 3, 4, 65, 27, 203, 236, 3489, 2845, 53471, 21341, 757913, 553973, 619181, 1040164, 29169263, 16276383, 193614199, 116220883, 32925391, 10628013, 320160667, 455451475, 22987116115, 19980510667, 193553388003, 154777722503

Offset

1,3

Links

Table of n, a(n) for n=1..28.

Formula

p divides a(p^k) for prime p and integer k>1. p divides a(p), a(2p) and a(2p^2) for prime p>2. - Alexander Adamchuk, Jul 27 2006

Mathematica

f[n_] := Block[{s = 0, d = 1}, While[d < n, If[ Mod[n, d] != 0, s = s + n/d]; d++ ]; s]; Numerator[ Table[ f[n], {n, 1, 28}]]

Crossrefs

Denominator = A027611. Cf. A049820, A024816.

Sequence in context: A196442 A349587 A278035 * A274699 A060356 A052323

Adjacent sequences: A079073 A079074 A079075 * A079077 A079078 A079079

Keyword

nonn,frac

Author

Reinhard Zumkeller, Dec 21 2002

Extensions

Edited and extended by Robert G. Wilson v, Dec 30 2002

Status

approved