English

Down-step statistics in generalized Dyck paths

Combinatorics 2023-06-22 v6 Discrete Mathematics

Abstract

The number of down-steps between pairs of up-steps in ktk_t-Dyck paths, a generalization of Dyck paths consisting of steps {(1,k),(1,1)}\{(1, k), (1, -1)\} such that the path stays (weakly) above the line y=ty=-t, is studied. Results are proved bijectively and by means of generating functions, and lead to several interesting identities as well as links to other combinatorial structures. In particular, there is a connection between ktk_t-Dyck paths and perforation patterns for punctured convolutional codes (binary matrices) used in coding theory. Surprisingly, upon restriction to usual Dyck paths this yields a new combinatorial interpretation of Catalan numbers.

Keywords

Cite

@article{arxiv.2007.15562,
  title  = {Down-step statistics in generalized Dyck paths},
  author = {Andrei Asinowski and Benjamin Hackl and Sarah J. Selkirk},
  journal= {arXiv preprint arXiv:2007.15562},
  year   = {2023}
}
R2 v1 2026-06-23T17:31:59.912Z