On Methods of Constructing Sets of Mutually Orthogonal Latin Squares Using a Computer. I

This paper deals with the problem of finding sets of mutually orthogonal Latin squares of order 4t (where 4t – 1 is a prime power) based on orthogonal mappings of a group. For the group G we take the module G(2, 2t) whose elements are vectors (a 1, a 2,) where a 1 is a residue class (mod 2) and a 2 is a residue class (mod 2t), the addition being defined by (a 1, a 2) + (b 1, b 2) = (c 1, c 2) where a 1 + b 1 = C 1 (mod 2) and a 2 + b 2 = c 2 (mod 2t). Then the search for orthogonal mappings is materially simplified by using a configuration based on the balanced incomplete block design with parameters v = b = 4t – 1, r = k = 2t – 1, λ = t – 1. Using this method, two sets of five mutually orthogonal Latin squares of order 12 were obtained.