A054013 Chowla function of n read modulo n.

0, 0, 0, 2, 0, 5, 0, 6, 3, 7, 0, 3, 0, 9, 8, 14, 0, 2, 0, 1, 10, 13, 0, 11, 5, 15, 12, 27, 0, 11, 0, 30, 14, 19, 12, 18, 0, 21, 16, 9, 0, 11, 0, 39, 32, 25, 0, 27, 7, 42, 20, 45, 0, 11, 16, 7, 22, 31, 0, 47, 0, 33, 40, 62, 18, 11, 0, 57, 26, 3, 0, 50, 0, 39, 48, 63, 18, 11, 0, 25, 39, 43, 0

Offset: 1

Author

Asher Auel, Jan 17 2000

Keywords

• nonn

Comments

Chowla's function (A048050) = sum of divisors of n except 1 and n.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..16384

Crossrefs

Cf. A048050, A054014, A054015.

Programs

Maple

with(numtheory): [seq((sigma(i) - i - 1) mod i, i=2..100)];

Mathematica

Table[Mod[DivisorSigma[1,n]-n-1,n],{n,90}] (* Harvey P. Dale, Dec 01 2011 *)

PARI

A054013(n) = ((sigma(n)-n-1) % n); \\ Antti Karttunen, Oct 30 2017

Formula

a(n) = A048050(n) mod n