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A New Type of Freeman-Youden Rectangle

D.A. Preece 1, N.CK. Phillips 2
1Institute of Mathematics and Statistics Cornwallis Building University of Kent at Canterbury Canterbury, Kent England CT2 7NF
2Computer Science Department Southern Illinois University Carbondale, Illinois USA 62901-4408

Abstract

A Freeman-Youden rectangle (FYR) is a Graeco-Latin row-column design consisting of a balanced superimposition of two Youden squares. There are well-known infinite series of FYRs of sizes \(q \times (2q + 1)\) and \((q+1) \times (2q+1)\), where \( (2q+1) \) is a prime power congruent to 3 (modulo 4). Any member of these series is readily constructed from an initial column whose entries are specified very simply in terms of powers of a primitive root of GF\((2q + 1)\).

We now show that, for \(q \geq 9\), initial columns for FYRs of the above sizes can be specified more generally, which allows us to obtain many more FYRs, which are unlike any that have previously appeared in the literature. We present enumerations for \(q = 9\) and \(q = 11\), and we tabulate new FYRs for these values of \(q\). We also present some new FYRs for \(q = 15\).