## Abstract

Abstract. Let Tn be the set of 321-avoiding permutations of order n.
Two properties of Tn are proved: (1) The last descent and last index
minus one statistics are equidistributed over Tn, and also over subsets
of permutations whose inverse has an (almost) prescribed descent set.An analogous result holds for Dyck paths. (2) The sign-and-last-descent enumerators for T2n and T2n+1 are essentially equal to the last-descent enumerator for Tn. The proofs use a recursion formula for an appropriate multivariate generating function.

Original language | American English |
---|---|

Pages (from-to) | 14-14 |

Journal | Seminaire Lotharingien de Combinatoire |

Volume | 51 |

State | Published - 2004 |