A326045 a(n) is the sum of divisors of n, minus the largest square dividing that sum, minus n: a(n) = sigma(n) - A008833(sigma(n)) - n.

-1, 0, -3, 2, 0, 2, -3, 6, 3, -1, -3, 12, 0, 6, 5, 14, -8, 20, -3, 21, -5, -22, -3, 32, 5, 15, 9, 24, 0, 6, -15, 22, -1, 11, -3, 54, 0, 18, 13, 41, 0, 38, -3, 36, 32, -10, -15, 72, 7, 42, -15, -3, -8, 62, -19, 60, 7, 23, -3, 104, 0, 18, 37, 62, 15, -66, -3, 49, 11, -70, -35, 122, 0, 39, 45, 60, 3, 86, -15, 105, -81, 35, -3

Offset

1,3

Links

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

Index entries for sequences related to sigma(n)

Formula

a(n) = A326040(n) - n = sigma(n) - A008833(sigma(n)) - n.

Prog

(PARI)
A008833(n) = (n/core(n));
A326039(n) = A008833(sigma(n));
A326040(n) = (sigma(n)-A008833(sigma(n)));
A326045(n) = (A326040(n)-n);

Crossrefs

Cf. A000203, A008833, A326039, A326040, A326044, A326046.

Sequence in context: A236603 A129576 A122861 * A277097 A077814 A131728

Adjacent sequences: A326042 A326043 A326044 * A326046 A326047 A326048

Keyword

sign

Author

Antti Karttunen, Jun 05 2019

Status

approved