A217326 Number of self-inverse permutations in S_n with longest increasing subsequence of length 6.

1, 6, 41, 209, 1106, 5323, 26069, 122901, 585922, 2747977, 13000269, 61088173, 289186846, 1366147708, 6496681304, 30905464864, 147912712795, 709073550307, 3418258506885, 16517431269189, 80230551304034, 390774361811783, 1912602871119956, 9388456361080840

Offset

6,2

Comments

Also the number of Young tableaux with n cells and 6 rows.

Links

Alois P. Heinz, Table of n, a(n) for n = 6..400

Formula

a(n) = A182172(n,6)-A182172(n,5) = A007579(n)-A049401(n).

Example

a(6) = 1: 123456.
a(7) = 6: 1234576, 1234657, 1235467, 1243567, 1324567, 2134567.

Crossrefs

Column k=6 of A047884.

Cf. A007579, A049401, A182172.

Sequence in context: A135232 A371536 A291890 * A196433 A197196 A295117

Adjacent sequences: A217323 A217324 A217325 * A217327 A217328 A217329

Keyword

nonn

Author

Alois P. Heinz, Sep 30 2012

Status

approved