## Multi-latin squares

##### Citation

Cavenagh, N.J., Hämäläinen, C., Lefevre, J.G. & Stones, D.S. (2010). Multi-latin squares. Discrete Mathematics, 311(13), 1164-1171.

Permanent Research Commons link: http://hdl.handle.net/10289/4207

##### Abstract

A multi-latin square of order n and index k is an n×n array of multisets, each of cardinality k, such that each symbol from a fixed set of size n occurs k times in each row and k times in each column. A multi-latin square of index k is also referred to as a k-latin square. A 1-latin square is equivalent to a latin square, so a multi-latin square can be thought of as a generalization of a latin square.
In this note we show that any partially filled-in k-latin square of order m embeds in a k-latin square of order n, for each n≥2m, thus generalizing Evans’ Theorem. Exploiting this result, we show that there exist non-separable k-latin squares of order n for each n≥k+2. We also show that for each n≥1, there exists some finite value g(n) such that for all k≥g(n), every k-latin square of order n is separable.
We discuss the connection between k-latin squares and related combinatorial objects such as orthogonal arrays, latin parallelepipeds, semi-latin squares and k-latin trades. We also enumerate and classify k-latin squares of small orders.

##### Date

2010##### Type

##### Publisher

Elsevier