Two Permutation Classes Enumerated by the Central Binomial Coefficients
Marilena Barnabei and Flavio Bonetti
Dipartimento di Matematica
Università di Bologna
Piazza di Porta San Donato 5
LaBRI — Université Bordeaux 1
351, cours de la Libération
We define a map between the set of permutations that avoid either the
four patterns 3214, 3241, 4213, 4231 or 3124, 3142, 4123, 4132, and the
set of Dyck prefixes. This map, when restricted to either of the two
classes, turns out to be a bijection that allows us to determine some
notable features of these permutations, such as the distribution of the
statistics "number of ascents", "number of left-to-right maxima", "first
element", and "position of the maximum element".
Full version: pdf,
(Concerned with sequence
Received January 9 2013;
revised version received February 24 2013.
Published in Journal of Integer Sequences, March 2 2013.
Journal of Integer Sequences home page