English

The Eulerian numbers on restricted centrosymmetric permutations

Combinatorics 2009-10-14 v1

Abstract

We study the descent distribution over the set of centrosymmetric permutations that avoid the pattern of length 3. Our main tool in the most puzzling case, namely, τ=123\tau=123 and nn even, is a bijection that associates a Dyck prefix of length 2n2n to every centrosymmetric permutation in S2nS_{2n} that avoids 123.

Keywords

Cite

@article{arxiv.0910.2376,
  title  = {The Eulerian numbers on restricted centrosymmetric permutations},
  author = {Marilena Barnabei and Flavio Bonetti and Matteo Silimbani},
  journal= {arXiv preprint arXiv:0910.2376},
  year   = {2009}
}

Comments

17 pages, 6 figures

R2 v1 2026-06-21T13:57:42.977Z