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A170815 Number of permutations of 1..n with all differences of elements separated by distances 1 through 9 being respectively unique. 0
1, 2, 4, 12, 40, 116, 200, 444, 760, 2160, 4368, 7852, 12828, 17252, 19612, 21104, 18276, 15096, 10240, 6464, 3776, 2536 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

(Empirical) Equals A008404 for n<=2m+2, where m is the maximum difference separation 9.

LINKS

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

CROSSREFS

Sequence in context: A180487 A000940 A008404 * A170814 A170813 A170812

Adjacent sequences:  A170812 A170813 A170814 * A170816 A170817 A170818

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 02 2009

STATUS

approved

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Last modified December 11 13:55 EST 2017. Contains 295876 sequences.