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A268949
Number of sequences in {1,...,2n}^(2n) with longest increasing subsequence of length n.
1
1, 3, 175, 23611, 5179791, 1583828620, 621893381187, 298289430051783, 169027530016448143, 110485582196129404780, 81829925127960010076736
OFFSET
0,2
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
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Feb 16 2016
STATUS
approved