A318675 Sum of squarefree divisors of n that have an odd number of prime factors.

0, 2, 3, 2, 5, 5, 7, 2, 3, 7, 11, 5, 13, 9, 8, 2, 17, 5, 19, 7, 10, 13, 23, 5, 5, 15, 3, 9, 29, 40, 31, 2, 14, 19, 12, 5, 37, 21, 16, 7, 41, 54, 43, 13, 8, 25, 47, 5, 7, 7, 20, 15, 53, 5, 16, 9, 22, 31, 59, 40, 61, 33, 10, 2, 18, 82, 67, 19, 26, 84, 71, 5, 73, 39, 8, 21, 18, 96, 79, 7, 3, 43, 83, 54, 22, 45, 32, 13, 89, 40, 20, 25, 34, 49, 24, 5

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Formula

For all n >= 1, a(n) <= A318677(n).

a(n) = Sum_{d|n} [A008683(d) < 0]*d.

a(n) = A048250(n) - A318674(n).

Mathematica

Array[DivisorSum[#, # &, MoebiusMu@ # == -1 &] &, 96] (* Michael De Vlieger, Sep 04 2018 *)

Prog

(PARI) A318675(n) = sumdiv(n, d, (-1==moebius(d))*d);

Crossrefs

Cf. A008472, A048250, A318320, A318674, A318677.

Sequence in context: A361630 A323171 A008472 * A123528 A374250 A074036

Adjacent sequences: A318672 A318673 A318674 * A318676 A318677 A318678

Keyword

nonn

Author

Antti Karttunen, Sep 04 2018

Status

approved