# The Eulerian numbers on restricted centrosymmetric permutations - Mathematics > Combinatorics

The Eulerian numbers on restricted centrosymmetric permutations - Mathematics > Combinatorics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We study the descent distribution over the set of centrosymmetricpermutations that avoid the pattern of length 3. Our main tool in the mostpuzzling case, namely, $\tau=123$ and $n$ even, is a bijection that associatesa Dyck prefix of length $2n$ to every centrosymmetric permutation in $S {2n}$that avoids 123.

Author: Marilena Barnabei, Flavio Bonetti, Matteo Silimbani

Source: https://arxiv.org/