A226287 a(n) = [n/2]!*[(n+1)/2]!*C([n/2],6)*C([(n+1)/2],6).

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 518400, 25401600, 1244678400, 39829708800, 1274550681600, 34412868403200, 929147446886400, 23228686172160000, 580717154304000000, 14053355134156800000, 340091194246594560000

Offset: 1

Author

R. H. Hardin, connection of formula with combinatoric problem via N. J. A. Sloane in the Sequence Fans Mailing List, Jun 02 2013

Keywords

• nonn

Comments

Number of permutations of n elements with 12 odd displacements.

Column 7 of A226288.

Column k=12 of A145893, a diagonal of A145894. - Alois P. Heinz, May 29 2014

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210