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
Keywords
Examples
a(0) = 1: the empty composition. a(1) = 1: 2. a(2) = 1: 22. a(3) = 4: 222, 114, 141, 411.
Links
- Vaclav Kotesovec, Table of n, a(n) for n = 0..131 (terms 0..100 from Alois P. Heinz)
Crossrefs
Cf. A242887.
Formula
a(n) = A242887(2n,n).