English

Quadrant marked mesh patterns in 132-avoiding permutations II

Combinatorics 2013-02-12 v1

Abstract

Given a permutation \sg=\sg1...\sgn\sg = \sg_1...\sg_n in the symmetric group SnS_n, we say that \sgi\sg_i matches the marked mesh pattern MMP(a,b,c,d)MMP(a,b,c,d) in \sg\sg if there are at least aa points to the right of \sgi\sg_i in \sg\sg which are greater than \sgi\sg_i, at least bb points to the left of \sgi\sg_i in \sg\sg which are greater than \sgi\sg_i, at least cc points to the left of \sgi\sg_i in \sg\sg which are smaller than \sgi\sg_i, and at least dd points to the right of \sgi\sg_i in \sg\sg which are smaller than \sgi\sg_i. This paper is continuation of the systematic study of the distribution of quadrant marked mesh patterns in 132-avoiding permutations started in \cite{kitremtie} where we mainly studied the distribution of the number of matches of MMP(a,b,c,d)MMP(a,b,c,d) in 132-avoiding permutations where exactly one of a,b,c,da,b,c,d is greater than zero and the remaining elements are zero. In this paper, we study the distribution of the number of matches of MMP(a,b,c,d)MMP(a,b,c,d) in 132-avoiding permutations where exactly two of a,b,c,da,b,c,d are greater than zero and the remaining elements are zero. We provide explicit recurrence relations to enumerate our objects which can be used to give closed forms for the generating functions associated with such distributions. In many cases, we provide combinatorial explanations of the coefficients that appear in our generating functions. The case of quadrant marked mesh patterns MMP(a,b,c,d)MMP(a,b,c,d) where three or more of a,b,c,da,b,c,d are constrained to be greater than 0 will be studied in \cite{kitremtieIII}.

Keywords

Cite

@article{arxiv.1302.2274,
  title  = {Quadrant marked mesh patterns in 132-avoiding permutations II},
  author = {Sergey Kitaev and Jeffrey Remmel and Mark Tiefenbruck},
  journal= {arXiv preprint arXiv:1302.2274},
  year   = {2013}
}
R2 v1 2026-06-21T23:23:42.252Z