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

1,4

Links

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

Formula

a(n) <= A338886(n).

Example

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).

Crossrefs

Cf. A228286, A338886.

Sequence in context: A251419 A036410 A008670 * A338886 A218950 A193748

Adjacent sequences: A338884 A338885 A338886 * A338888 A338889 A338890

Keyword

nonn

Author

Peter Kagey, Nov 14 2020

Status

approved