A170810 Number of permutations of 1..n with all differences of elements separated by distances 1 through 4 being respectively unique.

1, 2, 4, 12, 40, 116, 200, 444, 760, 2160, 4872, 11932, 29252, 71708, 191356, 536908, 1607592, 5184252, 17331516, 61597568, 228854684, 891958912

Offset: 1

Author

R. H. Hardin Dec 02 2009

Keywords

• nonn

Comments

(Empirical) Equals A008404 for n<=2m+2, where m is the maximum difference separation 4.