English

Block-avoiding point sequencings of Mendelsohn triple systems

Combinatorics 2019-09-20 v1

Abstract

A cyclic ordering of the points in a Mendelsohn triple system of order vv (or MTS(v)(v)) is called a sequencing. A sequencing DD is \ell-good if there does not exist a triple (x,y,z)(x,y,z) in the MTS(v)(v) such that (1) the three points x,y,x,y, and zz occur (cyclically) in that order in DD; and (2) {x,y,z}\{x,y,z\} is a subset of \ell cyclically consecutive points of DD. In this paper, we prove some upper bounds on \ell for MTS(v)(v) having \ell-good sequencings and we prove that any MTS(v)(v) with v7v \geq 7 has a 33-good sequencing. We also determine the optimal sequencings of every MTS(v)(v) with v10v \leq 10.

Keywords

Cite

@article{arxiv.1909.09101,
  title  = {Block-avoiding point sequencings of Mendelsohn triple systems},
  author = {Donald L. Kreher and Douglas R. Stinson and Shannon Veitch},
  journal= {arXiv preprint arXiv:1909.09101},
  year   = {2019}
}
R2 v1 2026-06-23T11:20:29.134Z