On a Refinement of Wilf-equivalence for Permutations

  • Sherry H.F. Yan
  • Huiyun Ge
  • Yaqiu Zhang

Abstract

Recently, Dokos et al. conjectured that for all $k, m\geq 1$, the patterns $ 12\ldots k(k+m+1)\ldots (k+2)(k+1) $ and $(m+1)(m+2)\ldots  (k+m+1)m\ldots 21$ are $maj$-Wilf-equivalent. In this paper, we confirm this conjecture for all $k\geq 1$ and $m=1$. In fact, we construct a descent set preserving bijection between $ 12\ldots k (k-1) $-avoiding permutations and $23\ldots k1$-avoiding permutations for all $k\geq 3$. As a corollary, our bijection enables us to settle a conjecture of  Gowravaram and Jagadeesan concerning the Wilf-equivalence for  permutations with given descent sets.

Published
2015-02-09
Article Number
P1.20