A175082 Possible values for sum of perfect divisors of n.

1, 2, 3, 5, 6, 7, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24, 26, 28, 29, 30, 31, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75

Offset: 1

Author

Jaroslav Krizek, Jan 24 2010

Keywords

• nonn

Comments

Perfect divisor of n is divisor d such that d^k = n for some k >= 1. See A175067 (sum of perfect divisors of n) and A175081 (values taken by the sum of perfect divisors of n (A175067) sorted into ascending order).

Complement of A001597(n+1) for n >= 1 (perfect powers >= 4). a(n) = A007916(n-1) for n >= 2. [From Jaroslav Krizek, Jan 30 2010]