A180888 Number of permutations of 0..n-1 with no element greater than or equal to the sum of its neighbors

1, 0, 0, 0, 8, 24, 80, 504, 4600, 36176, 304888, 2842472, 29790752, 331382672, 3962130640, 50186636768, 680693513480

Offset

1,5

Links

Table of n, a(n) for n=1..17.

Example

All solutions for n=5
(0 1 2 4 3) (0 1 3 4 2) (0 2 4 3 1) (0 3 4 2 1)
(1 2 4 3 0) (1 3 4 2 0) (2 4 3 1 0) (3 4 2 1 0)

Crossrefs

Sequence in context: A241690 A141317 A146534 * A296400 A297808 A097544

Adjacent sequences: A180885 A180886 A180887 * A180889 A180890 A180891

Keyword

nonn

Author

R. H. Hardin Sep 23 2010

Status

approved