A321772 Number of compositions of 2n into parts with distinct multiplicities and with exactly n parts.

1, 1, 1, 4, 5, 6, 142, 428, 1269, 3874, 20336, 114522, 429002, 1743184, 6456192, 23749014, 93997909, 368890906, 1122546076, 4496925530, 17437145160, 76147395524, 310155556998, 1417665712388, 5528899930962, 21923449788406, 82833896451112, 347234278501138

Offset

0,4

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..131 (terms 0..100 from Alois P. Heinz)

Formula

a(n) = A242887(2n,n).

Example

a(0) = 1: the empty composition.
a(1) = 1: 2.
a(2) = 1: 22.
a(3) = 4: 222, 114, 141, 411.

Crossrefs

Cf. A242887.

Sequence in context: A352865 A095212 A166042 * A333435 A146968 A298982

Adjacent sequences: A321769 A321770 A321771 * A321773 A321774 A321775

Keyword

nonn

Author

Alois P. Heinz, Nov 18 2018

Status

approved