Restricted Dumont permutations, Dyck paths, and noncrossing partitions

Burstein, Alexander; Elizalde, Sergi; Mansour, Toufik

Restricted Dumont permutations, Dyck paths, and noncrossing partitions

Authors

Burstein, Alexander

Elizalde, Sergi

Mansour, Toufik

Description

We complete the enumeration of Dumont permutations of the second kind avoiding a pattern of length 4 which is itself a Dumont permutation of the second kind. We also consider some combinatorial statistics on Dumont permutations avoiding certain patterns of length 3 and 4 and give a natural bijection between 3142-avoiding Dumont permutations of the second kind and noncrossing partitions that uses cycle decomposition, as well as bijections between 132-, 231- and 321-avoiding Dumont permutations and Dyck paths. Finally, we enumerate Dumont permutations of the first kind simultaneously avoiding certain pairs of 4-letter patterns and another pattern of arbitrary length.
20 pages, 5 figures