A326050 a(n) = A082052(n) - n, where A082052 is the sum of divisors of n that are not of the form 4k+1.

-1, 0, 0, 2, -5, 5, 0, 6, -6, 2, 0, 15, -13, 9, 3, 14, -17, 11, 0, 16, -11, 13, 0, 35, -25, 2, 3, 27, -29, 36, 0, 30, -19, 2, 7, 45, -37, 21, 3, 44, -41, 32, 0, 39, -27, 25, 0, 75, -42, 12, 3, 32, -53, 56, 11, 63, -35, 2, 0, 102, -61, 33, 10, 62, -65, 44, 0, 40, -43, 68, 0, 113, -73, 2, 18, 63, -59, 76, 0, 100, -51, 2, 0, 118, -85, 45, 3

Offset: 1

Author

Antti Karttunen, Jun 04 2019

Keywords

• sign

Links

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

Crossrefs

Cf. A033879, A082052, A326048, A326049.

Programs

Mathematica

Table[Total[Select[Divisors[n],Mod[#-1,4]!=0&]]-n,{n,90}] (* Harvey P. Dale, Jul 12 2024 *)

PARI

A082052(n) = sumdiv(n, d, if(1!=(d%4), d));
A326050(n) = (A082052(n)-n);

Formula

a(n) = A082052(n) - n.

a(n) = A326049(n) - A033879(n).