A217321 Number of self-inverse permutations in S_n with longest increasing subsequence of length 9.

1, 9, 89, 639, 4655, 30330, 198148, 1233743, 7694099, 46938514, 287070944, 1738940782, 10570927022, 64059763010, 389873574058, 2373799261605, 14522526860316, 89060416668016, 548932942208392, 3395326330414774, 21109553761623110, 131785019270029876

Offset: 9

Author

Alois P. Heinz, Sep 30 2012

Keywords

• nonn

Comments

Also the number of Young tableaux with n cells and 9 rows.

Links

• Alois P. Heinz, Table of n, a(n) for n = 9..350

Crossrefs

Column k=9 of A047884.

Cf. A007580, A182172, A212915.

Formula

a(n) = A182172(n,9)-A182172(n,8) = A212915(n)-A007580(n).