Article ID Journal Published Year Pages File Type
4647660 Discrete Mathematics 2013 8 Pages PDF
Abstract

Two Latin squares of order nn are rr-orthogonal if their superposition produces exactly rr distinct ordered pairs. If one of the two squares is the transpose of the other, we say that the square is rr-self-orthogonal, denoted by r-SOLS(n). It has been proved by Xu and Chang that the necessary and sufficient condition for the existence of an r-SOLS(n) is n≤r≤n2n≤r≤n2 and r∉{n+1,n2−1}r∉{n+1,n2−1} with 26 genuine exceptions and 26 possible exceptions. In this paper, we provide 25 new Latin squares to reduce the possible exceptions from 26 to one, i.e.,  (n,r)=(14,142−3)(n,r)=(14,142−3). We also provide an idempotent incomplete self-orthogonal Latin square (ISOLS) of order 26 with a hole of size 8.

Related Topics
Physical Sciences and Engineering Mathematics Discrete Mathematics and Combinatorics
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