A054015 a(n) is Chowla function of n read modulo (number of proper divisors of n), a(1) = 0 by convention.

0, 0, 0, 0, 0, 2, 0, 0, 1, 1, 0, 0, 0, 0, 2, 2, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 2, 0, 6, 0, 0, 2, 1, 0, 6, 0, 0, 1, 0, 0, 4, 0, 4, 2, 1, 0, 3, 1, 2, 2, 0, 0, 2, 1, 0, 1, 1, 0, 8, 0, 0, 0, 2, 0, 0, 0, 2, 2, 3, 0, 1, 0, 0, 3, 3, 0, 5, 0, 6, 3, 1, 0, 7, 1, 0, 2, 0, 0, 0, 2, 0, 1, 1, 0, 1, 0, 2, 1, 4, 0, 1, 0, 0, 2

Offset

1,6

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

Index entries for sequences related to sums of divisors

Formula

a(1) = 0; for n > 1, a(n) = A048050(n) mod A032741(n).

Maple

with(numtheory): [seq((sigma(i)-i-1) mod (tau(i)-1), i=2..120); #i>1

Prog

(PARI) A054015(n) = if(1==n, 0, ((sigma(n)-n-1) % (numdiv(n)-1))); \\ Antti Karttunen, Oct 20 2017

Crossrefs

Cf. A032741, A048050, A054013, A054014.

Sequence in context: A373898 A112609 A134363 * A375933 A373976 A369164

Adjacent sequences: A054012 A054013 A054014 * A054016 A054017 A054018

Keyword

nonn

Author

Asher Auel, Jan 17 2000

Extensions

Description clarified by Antti Karttunen, Oct 20 2017

Status

approved