A324365 Number of permutations p of [n] having no index i with |p(i)-i| = 3.

1, 1, 2, 6, 14, 53, 265, 1554, 11024, 90816, 846032, 8803826, 101011765, 1265197857, 17167351014, 250725968406, 3920074915626, 65310957981693, 1154885557082749, 21599009876309400, 425919898969718528, 8831294211199266816, 192065262001816123136

Offset

0,3

Links

Alois P. Heinz, Table of n, a(n) for n = 0..250

Wikipedia, Permutation

Formula

a(n) = n! - A324366(n).

Example

a(4) = 14: 1234, 1243, 1324, 1342, 1423, 1432, 2134, 2143, 2314, 2413, 3124, 3142, 3214, 3412.

Crossrefs

Column k=3 of A306512.

Cf. A000142, A324366.

Sequence in context: A355093 A376075 A295974 * A346208 A354533 A192764

Adjacent sequences: A324362 A324363 A324364 * A324366 A324367 A324368

Keyword

nonn

Author

Alois P. Heinz, Feb 23 2019

Status

approved