English

$(p,q,t)$-Catalan continued fractions, gamma expansions and pattern avoidances

Combinatorics 2023-05-09 v2

Abstract

We introduce a kind of (p,q,t)(p, q, t)-Catalan numbers of Type A by generalizing the Jacobian type continued fraction formula, we proved that the corresponding expansions could be expressed by the polynomials counting permutations on §n(321)\S_n(321) by various descent statistics. Moreover, we introduce a kind of (p,q,t)(p, q, t)-Catalan numbers of Type B by generalizing the Jacobian type continued fraction formula, we proved that the Taylor coefficients and their γ\gamma-coefficients could be expressed by the polynomials counting permutations on §n(3124,4123,3142,4132)\S_n(3124, 4123, 3142, 4132) by various descent statistics. Our methods include permutation enumeration techniques involving variations of bijections from permutation patterns to labeled Motzkin paths and modified Foata-Strehl action.

Keywords

Cite

@article{arxiv.2211.10893,
  title  = {$(p,q,t)$-Catalan continued fractions, gamma expansions and pattern avoidances},
  author = {Bin Han and Qiongqiong Pan},
  journal= {arXiv preprint arXiv:2211.10893},
  year   = {2023}
}
R2 v1 2026-06-28T06:17:53.244Z