A338935 a(n) = Sum_{d|n} (d^2 mod n).

0, 1, 1, 1, 1, 8, 1, 5, 1, 10, 1, 18, 1, 12, 20, 5, 1, 23, 1, 26, 17, 16, 1, 58, 1, 18, 10, 42, 1, 70, 1, 21, 32, 22, 40, 39, 1, 24, 23, 90, 1, 106, 1, 54, 71, 28, 1, 98, 1, 55, 44, 34, 1, 104, 37, 106, 29, 34, 1, 240, 1, 36, 77, 21, 65, 160, 1, 38, 56, 200, 1, 175, 1, 42, 60, 78, 94, 154, 1, 146

Offset

1,6

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(6) = (1^2 mod 6) + (2^2 mod 6) + (3^2 mod 6) + (6^2 mod 6) = 1+4+3+0 = 8.

Maple

f:= n -> add(t^2 mod n, t = numtheory:-divisors(n)):
map(f, [$1..100]);

Mathematica

Table[Total[Mod[Divisors[n]^2, n]], {n, 80}] (* Harvey P. Dale, Oct 11 2021 *)

Prog

(PARI) a(n) = sumdiv(n, d, lift(Mod(d, n)^2)); \\ Michel Marcus, Nov 16 2020

Crossrefs

Cf. A000430 (a(n)=1), A338930 (a(n) is prime).

Sequence in context: A280040 A202284 A231772 * A200120 A154861 A153495

Adjacent sequences: A338932 A338933 A338934 * A338936 A338937 A338938

Keyword

nonn

Author

J. M. Bergot and Robert Israel, Nov 16 2020

Status

approved