A284152 a(n) = Sum_{d|n, d == 2 or 3 mod 5} d.
0, 2, 3, 2, 0, 5, 7, 10, 3, 2, 0, 17, 13, 9, 3, 10, 17, 23, 0, 2, 10, 24, 23, 25, 0, 15, 30, 37, 0, 5, 0, 42, 36, 19, 7, 35, 37, 40, 16, 10, 0, 54, 43, 24, 3, 25, 47, 73, 7, 2, 20, 67, 53, 50, 0, 45, 60, 60, 0, 17, 0, 64, 73, 42, 13, 60, 67, 87, 26, 9, 0, 115, 73
Offset: 1
Keywords
Examples
Divisors of 12 are 1 2 3 4 6 12. And 2 == 12 mod 5. We get a(12) = 2 + 3 + 12 = 17.
Links
- Seiichi Manyama, Table of n, a(n) for n = 1..10000
Formula
a(n) = A000203(n) -5*A000203(n/5) -A284150(n), where A000203(.) =0 for non-integer arguments. - R. J. Mathar, Mar 21 2017