A338887 a(n) is the size of the set {x + y*z | x*y + z = n}, where x, y, and z are positive integers.

0, 1, 1, 2, 3, 3, 5, 6, 7, 9, 12, 10, 14, 15, 16, 19, 23, 19, 27, 24, 28, 30, 34, 30, 42, 38, 39, 39, 48, 42, 58, 50, 53, 56, 65, 51, 71, 67, 67, 68, 85, 68, 88, 76, 82, 85, 98, 76, 107, 95, 101, 94, 117, 96, 118, 108, 114, 121, 137, 100, 142, 131, 134, 130, 154

Offset: 1

Author

Peter Kagey, Nov 14 2020

Keywords

• nonn

Examples

			The a(7) = 5 solutions are:
2 + 3 * 1 =  5 (corresponding to 2 * 3 + 1 = 7),
1 + 6 * 1 =  7 (corresponding to 1 * 6 + 1 = 7),
2 + 2 * 3 =  8 (corresponding to 2 * 2 + 3 = 7),
1 + 5 * 2 = 11 (corresponding to 1 * 5 + 2 = 7), and
1 + 4 * 3 = 13 (corresponding to 1 * 4 + 3 = 7).
		

Links

• Peter Kagey, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A228286, A338886.

Formula

a(n) <= A338886(n).