Abstract
Two n× n Latin squares L1, L2 are said to be orthogonal if, for every ordered pair (x, y) of symbols, there are coordinates (i, j) such that L1(i, j) = x and L2(i, j) = y. A k-MOLS is a sequence of k pairwise-orthogonal Latin squares, and the existence and enumeration of these objects has attracted a great deal of attention. Recent work of Keevash and Luria provides, for all fixed k, log-asymptotically tight bounds on the number of k-MOLS. To study the situation when k grows with n, we bound the number of ways a k-MOLS can be extended to a (k+ 1) -MOLS. These bounds are again tight for constant k, and allow us to deduce upper bounds on the total number of k-MOLS for all k. These bounds are close to tight even for k linear in n, and readily generalise to the broader class of gerechte designs, which include Sudoku squares.
Original language | English |
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Pages (from-to) | 2187-2206 |
Number of pages | 20 |
Journal | Designs, Codes, and Cryptography |
Volume | 88 |
Issue number | 10 |
DOIs | |
Publication status | Published - 1 Oct 2020 |
Bibliographical note
Funding Information:S. Boyadzhiyska was supported by the Deutsche Forschungsgemeinschaft (DFG) Graduiertenkolleg “Facets of Complexity” (GRK 2434). S. Das was supported in part by the Deutsche Forschungsgemeinschaft (DFG) Project 415310276. S. Das and T. Szabó were supported in part by the German-Israeli Foundation for Scientific Research and Development (GIF) Grant G-1347-304.6/2016.
Publisher Copyright:
© 2020, The Author(s).
Keywords
- Gerechte designs
- Latin squares
- Orthogonal mates
ASJC Scopus subject areas
- Computer Science Applications
- Applied Mathematics