A217823 Number of permutations of length 3n with descent set {3, 6, ...} that avoid a certain pattern of length 4 or 5 (see Lewis, 2012, Appendix, for precise definition).

1, 1, 9, 153, 3579, 101630, 3288871

Offset

0,3

Comments

Is this the same sequence as A361190?

Links

Table of n, a(n) for n=0..6.

J. B. Lewis, Pattern Avoidance for Alternating Permutations and Reading Words of Tableaux, Ph. D. Dissertation, Department of Mathematics, MIT, 2012.

Crossrefs

Cf. A181197, A217799-A217830, A361190.

Sequence in context: A228713 A151835 A217822 * A361190 A113391 A045755

Adjacent sequences: A217820 A217821 A217822 * A217824 A217825 A217826

Keyword

nonn,more

Author

N. J. A. Sloane, Oct 13 2012

Extensions

a(5)-a(6) from Lars Blomberg, Mar 09 2018

a(0)=1 prepended by Alois P. Heinz, Jul 31 2023

Status

approved