A054025 - OEIS

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A054025

Sum of divisors of n read modulo (number of divisors of n).

12

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

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OFFSET

1,8

COMMENTS

a(A003601(n)) = 0; a(A049642(n)) > 0. [Reinhard Zumkeller, Jan 06 2012]

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A000203(n) mod A000005(n), sigma(n) mod tau(n).

MAPLE

with(numtheory): seq(sigma(i) mod tau(i), i=1..120);

MATHEMATICA

Table[Mod[DivisorSigma[1, n], DivisorSigma[0, n]], {n, 110}] (* Harvey P. Dale, Nov 16 2011 *)

PROG

(Haskell)

import Data.List (genericIndex)

a054025 n = genericIndex a054025_list (n-1)

a054025_list = zipWith mod a000203_list a000005_list

-- Reinhard Zumkeller, Jul 28 2014, Jan 06 2012

(PARI) vector(90, n, sigma(n) % numdiv(n)) \\ Michel Marcus, Aug 15 2015

CROSSREFS

Cf. A000005, A000203.

Cf. A003601, A049642, A245656.

Sequence in context: A359793 A074735 A074090 * A265910 A222212 A318526

Adjacent sequences: A054022 A054023 A054024 * A054026 A054027 A054028

KEYWORD

nonn

AUTHOR

Asher Auel, Jan 19 2000

STATUS

approved