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

Author

Alois P. Heinz, Feb 23 2019

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column k=3 of A306512.

Cf. A000142, A324366.

Formula

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