{ "id": "math/0509410", "version": "v1", "published": "2005-09-19T00:48:42.000Z", "updated": "2005-09-19T00:48:42.000Z", "title": "Latin squares and their defining sets", "authors": [ "Karola Meszaros" ], "comment": "16 pages, 24 figures", "categories": [ "math.CO" ], "abstract": "A Latin square $L(n,k)$ is a square of order $n$ with its entries colored with $k$ colors so that all the entries in a row or column have different colors. Let $d(L(n,k))$ be the minimal number of colored entries of an $n \\times n$ square such that there is a unique way of coloring of the yet uncolored entries in order to obtain a Latin square $L(n, k)$. In this paper we discuss the properties of $d(L(n,k))$ for $k=2n-1$ and $k=2n-2$. We give an alternate proof of the identity $d(L(n, 2n-1))=n^2-n$, which holds for even $n$, and we establish the new result $d(L(n, 2n-2)) \\geq n^2-\\lfloor\\frac{8n}{5}\\rfloor$ and show that this bound is tight for $n$ divisible by 10.", "revisions": [ { "version": "v1", "updated": "2005-09-19T00:48:42.000Z" } ], "analyses": { "subjects": [ "05B15" ], "keywords": [ "latin square", "defining sets", "minimal number", "unique way", "alternate proof" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2005math......9410M" } } }