A178847 Number of permutations of 4..n+3 with no element divisible by an adjacent element.

1, 2, 6, 24, 72, 480, 2640, 23040, 128640, 1444320, 14549760, 159007680, 1556058240, 24239980800, 301025439360, 5305897094400, 63948561909120, 1139924740993920

Offset

1,2

Links

Table of n, a(n) for n=1..18.

Crossrefs

Sequence in context: A087645 A174700 A216158 * A173844 A107761 A147943

Adjacent sequences: A178844 A178845 A178846 * A178848 A178849 A178850

Keyword

nonn

Author

R. H. Hardin Jun 17 2010

Status

approved