

A217830


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).


32




OFFSET

1,2


LINKS

Table of n, a(n) for n=1..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, A217799A217830.
Sequence in context: A237429 A177611 A051847 * A002115 A223498 A054949
Adjacent sequences: A217827 A217828 A217829 * A217831 A217832 A217833


KEYWORD

nonn,more


AUTHOR

N. J. A. Sloane, Oct 13 2012


EXTENSIONS

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


STATUS

approved



