A170813 Number of permutations of 1..n with all differences of elements separated by distances 1 through 7 being respectively unique.

1, 2, 4, 12, 40, 116, 200, 444, 760, 2160, 4368, 7852, 12828, 17252, 19612, 21104, 19760, 20392, 20128, 20636, 22408, 23988

Offset

1,2

Comments

(Empirical) Equals A008404 for n<=2m+2, where m is the maximum difference separation 7.

Links

Table of n, a(n) for n=1..22.

Crossrefs

Sequence in context: A008404 A170815 A170814 * A170812 A170811 A170810

Adjacent sequences: A170810 A170811 A170812 * A170814 A170815 A170816

Keyword

nonn

Author

R. H. Hardin Dec 02 2009

Status

approved