A174083 Number of circular permutations of length n with no consecutive triples (i, i+d, i+2d) (mod n) for all d.

4, 0, 40, 168, 1652, 9408, 117896, 1019260, 12737856, 140794368

Offset

4,1

Comments

Circular permutations are permutations whose indices are from the ring of integers modulo n.

Links

Table of n, a(n) for n=4..13.

Example

For n=5 since a(5)=0 all (5-1)! = 24 circular permutations of length 5 have some consecutive triple (i, i+d, i+2d) (mod 5). For example, the permutation (0,4,2,1,3) has a triple (1,3,0) with d=2. This is clearly a special case.

Crossrefs

Cf. A165962, A174075, A174080, A174081, A174082.

Sequence in context: A270184 A271300 A271120 * A123936 A271834 A138546

Adjacent sequences: A174080 A174081 A174082 * A174084 A174085 A174086

Keyword

nonn,more

Author

Isaac Lambert, Mar 15 2010

Extensions

a(10)-a(13) from Andrey Goder, Jul 03 2022

Status

approved