Constructions for mutually orthogonal frequency hyperrectangles with a prescribed type (Q5957747)

A \(d\)-dimensional array is a frequency hyperrectangle of type \(t\) if whenever any \(t\) of the coordinates are fixed, all symbols occur equally often in the subarray. Two frequency hyperrectangles are orthogonal if upon superposition, each ordered pair of symbols appears equally often. In this paper, the authors presented two different ways to construct orthogonal frequency hyperrectangles.