A268949 Number of sequences in {1,...,2n}^(2n) with longest increasing subsequence of length n.

1, 3, 175, 23611, 5179791, 1583828620, 621893381187, 298289430051783, 169027530016448143, 110485582196129404780, 81829925127960010076736

Offset

0,2

Links

Table of n, a(n) for n=0..10.

Formula

a(n) = A245667(2n,n).

Example

a(1) = 3: 11, 21, 22.
a(2) = 175: 1112, 1113, 1114, 1121, ..., 4414, 4423, 4424, 4434.

Crossrefs

Cf. A245667.

Sequence in context: A299462 A300105 A125711 * A113270 A091324 A198446

Adjacent sequences: A268946 A268947 A268948 * A268950 A268951 A268952

Keyword

nonn

Author

Alois P. Heinz, Feb 16 2016

Status

approved