login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A054025 Sum of divisors of n read modulo (number of divisors of n). 11
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 (list; graph; refs; listen; history; text; internal format)
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: A190561 A074735 A074090 * A265910 A222212 A318526

Adjacent sequences:  A054022 A054023 A054024 * A054026 A054027 A054028

KEYWORD

nonn

AUTHOR

Asher Auel (asher.auel(AT)reed.edu), Jan 19 2000

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 4 13:03 EST 2021. Contains 349526 sequences. (Running on oeis4.)