English

Cycles on a multiset with only even-odd drops

Combinatorics 2021-08-10 v1

Abstract

For a finite subset AA of Z>0\mathbb{Z}_{>0}, Lazar and Wachs (2019) conjectured that the number of cycles on AA with only even-odd drops is equal to the number of D-cycles on AA. In this note, we introduce cycles on a multiset with only even-odd drops and prove bijectively a multiset version of their conjecture. As a consequence, the number of cycles on [2n][2n] with only even-odd drops equals the Genocchi number gng_n. With Laguerre histories as an intermediate structure, we also construct a bijection between a class of permutations of length 2n12n-1 known to be counted by gng_n invented by Dumont and the cycles on [2n][2n] with only even-odd drops.

Cite

@article{arxiv.2108.03790,
  title  = {Cycles on a multiset with only even-odd drops},
  author = {Zhicong Lin and Sherry H. F. Yan},
  journal= {arXiv preprint arXiv:2108.03790},
  year   = {2021}
}

Comments

7 pages, 2 figures

R2 v1 2026-06-24T04:56:03.046Z