A309505 Number of cyclic permutations of length n that avoid the pattern 132 (equivalently, 213).

1, 1, 2, 4, 10, 24, 68, 182, 544, 1574, 4888, 14864

Offset

1,3

Links

Table of n, a(n) for n=1..12.

Miklos Bona, Michael Cory, Cyclic Permutations Avoiding Pairs of Patterns of Length Three, arXiv:1805.05196 [math.CO], 2018.

Brice Huang, An Upper Bound on the Number of (132,213)-Avoiding Cyclic Permutations, arXiv:1808.08462 [math.CO], 2018-2019.

Example

For n=3, there are two such permutations, 231 and 312.

Crossrefs

Cf. A309504, A309506, A309508.

Sequence in context: A151516 A003104 A121186 * A309504 A148088 A028506

Adjacent sequences: A309502 A309503 A309504 * A309506 A309507 A309508

Keyword

nonn,more

Author

Miklos Bona, Aug 05 2019

Status

approved