A082909 -id:A082909 - cp's OEIS frontend

A093061 6 * Sum_{d|n} (d mod 3).

6, 18, 6, 24, 18, 18, 12, 36, 6, 36, 18, 24, 12, 36, 18, 42, 18, 18, 12, 54, 12, 36, 18, 36, 24, 36, 6, 48, 18, 36, 12, 54, 18, 36, 36, 24, 12, 36, 12, 72, 18, 36, 12, 54, 18, 36, 18, 42, 18, 54, 18, 48, 18, 18, 36, 72, 12, 36, 18, 54, 12, 36, 12, 60, 36, 36, 12, 54, 18, 72, 18, 36, 12

Offset: 1

N. J. A. Sloane, Nov 02 2008

The old entry with this sequence number was a duplicate of A090331.

Cf. A004016, A082909.

Table[6 Sum[Mod[d, 3], {d, Divisors[n]}], {n, 50}] (* Wesley Ivan Hurt, May 28 2014 *)

a(n) = 6*sumdiv(n, d, d % 3); \\ Michel Marcus, May 26 2014

a(n) = 6*A082909(n). - Michel Marcus, May 26 2014

A353776 a(n) = Sum_{d|n} (n/d mod d).

Original entry on oeis.org

0, 1, 1, 1, 1, 4, 1, 3, 1, 4, 1, 7, 1, 4, 6, 3, 1, 7, 1, 8, 5, 4, 1, 14, 1, 4, 4, 10, 1, 14, 1, 7, 6, 4, 8, 11, 1, 4, 5, 17, 1, 16, 1, 10, 13, 4, 1, 19, 1, 9, 6, 8, 1, 16, 7, 17, 5, 4, 1, 32, 1, 4, 13, 7, 9, 19, 1, 8, 6, 23, 1, 27, 1, 4, 10, 10, 12, 16, 1, 23

Offset: 1

Sebastian Karlsson, May 07 2022

nonn

Antti Karttunen, Table of n, a(n) for n = 1..20000

Cf. A055155, A057670, A082909.

import Math.NumberTheory.ArithmeticFunctions
a n = sum $ map (\d -> n `quot` d `rem` d) $ divisorsList n

a[n_] := DivisorSum[n, Mod[n/#, #] &]; Array[a, 100] (* Amiram Eldar, May 07 2022 *)

A353776(n) = sumdiv(n,d,((n/d)%d)); \\ Antti Karttunen, May 08 2022

cp's OEIS Frontend

A093061 6 * Sum_{d|n} (d mod 3).

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