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

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

Author

Sebastian Karlsson, May 07 2022

Keywords

• nonn

Links

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

Crossrefs

Cf. A055155, A057670, A082909.

Programs

Haskell

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

Mathematica

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

PARI

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