A154658 Number of permutations of length n within distance 9.

1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 33022080, 277280640, 2184341040, 16427628720, 119892387720, 861175365144, 6157828055310, 44222780245622, 321113303226243, 2369364111428885, 17667206334000068, 132553643382927196, 997400200347756816

Offset: 0

Author

Torleiv Kløve, Jan 13 2009

Keywords

• nonn

Comments

a(n) equals the permanent of the n X n matrix with 1's along the central nineteen diagonals, and 0's everywhere else. - John M. Campbell, Jul 10 2011

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..400 (terms n=1..45 from R. H. Hardin)
• Torleiv Kløve, Spheres of Permutations under the Infinity Norm - Permutations with limited displacement, Reports in Informatics, Department of Informatics, University of Bergen, Norway, no. 376, November 2008.

Crossrefs

Cf. A000045, A002524, A002526, A072856, A154654-A154657.

Column k=9 of A306209.

Extensions

a(0)=1 prepended by Alois P. Heinz, Jan 28 2019