{ "id": "1909.09101", "version": "v1", "published": "2019-09-19T17:18:03.000Z", "updated": "2019-09-19T17:18:03.000Z", "title": "Block-avoiding point sequencings of Mendelsohn triple systems", "authors": [ "Donald L. Kreher", "Douglas R. Stinson", "Shannon Veitch" ], "categories": [ "math.CO" ], "abstract": "A cyclic ordering of the points in a Mendelsohn triple system of order $v$ (or MTS$(v)$) is called a sequencing. A sequencing $D$ is $\\ell$-good if there does not exist a triple $(x,y,z)$ in the MTS$(v)$ such that (1) the three points $x,y,$ and $z$ occur (cyclically) in that order in $D$; and (2) $\\{x,y,z\\}$ is a subset of $\\ell$ cyclically consecutive points of $D$. In this paper, we prove some upper bounds on $\\ell$ for MTS$(v)$ having $\\ell$-good sequencings and we prove that any MTS$(v)$ with $v \\geq 7$ has a $3$-good sequencing. We also determine the optimal sequencings of every MTS$(v)$ with $v \\leq 10$.", "revisions": [ { "version": "v1", "updated": "2019-09-19T17:18:03.000Z" } ], "analyses": { "subjects": [ "05B07" ], "keywords": [ "mendelsohn triple system", "block-avoiding point sequencings", "upper bounds", "optimal sequencings", "cyclically consecutive points" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }