A223034 Number of 3-vexillary permutations in S_n, that is, permutations whose Stanley symmetric function has at most 3 terms or at most 3 Edelman-Greene tableaux.

1, 1, 2, 6, 24, 120, 705, 4553, 30930, 216412, 1545469

Offset

0,3

Comments

This family is characterized by a finite set of permutation patterns.

Links

Table of n, a(n) for n=0..10.

S. Billey and B. Pawlowski, Permutation Patterns, Stanley symmetric functions and generalized Specht modules, arXiv:1304.7870 [math.CO], 2013.

Elizabeth Hartung, Hung Phuc Hoang, Torsten Mütze, Aaron Williams, Combinatorial generation via permutation languages. I. Fundamentals, arXiv:1906.06069 [cs.DM], 2019.

Crossrefs

Cf. A005802, A223905, A224318, A224287.

Sequence in context: A177525 A177532 A242573 * A177530 A324134 A324135

Adjacent sequences: A223031 A223032 A223033 * A223035 A223036 A223037

Keyword

nonn,more

Author

Sara Billey, Apr 04 2013

Extensions

a(0)=1 prepended by Alois P. Heinz, Jul 31 2019

Status

approved