A131502 Half the number of permutations of 0..n with a zero n-th difference.

0, 0, 1, 1, 8, 3, 136, 29, 928, 942, 66496, 6175, 2785856, 205678, 11122048

Offset

0,5

Links

Table of n, a(n) for n=0..14.

Example

a(5)=3 because 0,1,2,3,4,5 ; 0,2,4,3,1,5 ; and 0,4,2,1,3,5 ; and their reverses have zero 5th differences.

Crossrefs

Sequence in context: A038281 A302370 A303086 * A302891 A303626 A100253

Adjacent sequences: A131499 A131500 A131501 * A131503 A131504 A131505

Keyword

nonn

Author

R. H. Hardin, Aug 13 2007

Status

approved