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A054013 Chowla function of n read modulo n. 7
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

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

FORMULA

a(n) = A048050(n) mod n

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 *)

PROG

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

CROSSREFS

Cf. A048050, A054014, A054015.

Sequence in context: A257013 A104755 A242690 * A048050 A329375 A078153

Adjacent sequences: A054010 A054011 A054012 * A054014 A054015 A054016

KEYWORD

nonn

AUTHOR

Asher Auel (asher.auel(AT)reed.edu), Jan 17 2000

STATUS

approved

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Last modified December 3 09:50 EST 2022. Contains 358517 sequences. (Running on oeis4.)