A182473 Number of partitions of n into exactly 2 different parts with distinct multiplicities.

0, 0, 0, 0, 1, 3, 3, 8, 9, 12, 16, 22, 20, 31, 35, 34, 44, 51, 53, 62, 65, 68, 87, 86, 89, 95, 118, 108, 126, 127, 138, 142, 162, 154, 188, 160, 193, 189, 227, 204, 228, 221, 258, 238, 282, 247, 311, 272, 320, 284, 344, 318, 373, 327, 398, 334, 407, 380, 450

Offset: 0

Author

Alois P. Heinz, Apr 30 2012

Keywords

• nonn
• look

Examples

			a(4) = 1: [2,1,1], part 2 occurs once and part 1 occurs twice.
a(5) = 3: [2,1,1,1], [2,2,1], [3,1,1].
a(6) = 3: [2,1,1,1,1], [3,1,1,1], [4,1,1].
a(7) = 8: [2,1,1,1,1,1], [2,2,1,1,1], [2,2,2,1], [3,1,1,1,1], [3,2,2], [3,3,1], [4,1,1,1], [5,1,1].
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..3000

Crossrefs

Column k=2 of A182485.

Cf. A242900 (the same for compositions).