4 papers
Coincidences and Growth of Boxed Mesh Patterns
Sergey Kitaev, Dun Qiu, Chao Xu
A boxed mesh pattern is a mesh pattern whose selected entries lie in an empty axis-parallel rectangle. We classify coincidences of boxed patterns with classical and vincular patter…
A Refinement of the Fixed--Pixed Points Equidistribution on restricted Permutations
Yao Dong, Chao Xu
Motivated by a recent conjecture of Bsila, Cox, Hugo, Styron and Zhuang concerning fixed points and pixed points on pattern-avoiding permutations, we prove a bivariate refinement i…
A bi-Stirling-Euler-Mahonian polynomial
Chao Xu, Jiang Zeng
Motivated by recent work on (re)mixed Eulerian numbers, we provide a combinatorial interpretation of a subfamily of the remixed Eulerian numbers introduced by Nadeau and Tewari. Mo…
Gamma positivity of variations of -Eulerian polynomials
Chao Xu, Jiang Zeng
In 1977 Carlitz and Scoville introduced the cycle -Eulerian polynomials by enumerating permutations with respect to the number of excedanc…