Equidistant permutation arrays: a bound

Abstract An equidistant permutation array is a ν × r array A(r, λ;ν) defined on a r-set X such that every row of A is a permutation of X and any two distinct rows agree in precisely λ common columns. Define In this paper, we show that where n = r − λ. Certain results pertaining to irreducible equidistant permutation arrays are also established.