English

Skew Dyck paths having no peaks at level 1

Combinatorics 2022-01-26 v1

Abstract

Skew Dyck paths are a variation of Dyck paths, where additionally to steps (1,1)(1,1) and (1,1)(1,-1) a south-west step (1,1)(-1,-1) is also allowed, provided that the path does not intersect itself. Replacing the south-west step by a red south-east step, we end up with decorated Dyck paths. Sequence A128723 of the Encyclopedia of Integer Sequences considers such paths where peaks at level 1 are forbidden. We provide a thorough analysis of a more general scenario, namely partial decorated Dyck paths, ending on a prescribed level jj, both from left-to-right and from right-to-left (decorated Dyck paths are not symmetric). The approach is completely based on generating functions.

Keywords

Cite

@article{arxiv.2201.00640,
  title  = {Skew Dyck paths having no peaks at level 1},
  author = {Helmut Prodinger},
  journal= {arXiv preprint arXiv:2201.00640},
  year   = {2022}
}

Comments

arXiv admin note: text overlap with arXiv:2111.14797

R2 v1 2026-06-24T08:38:36.285Z