A frequency n-cube Fn(4;2,2) is an n-dimensional 4Γβ―Γ4 array filled by 0s and 1s such that each line contains exactly two 1s.
We classify the frequency 4-cubes F4(4;2,2), find a testing set of size
25 for F3(4;2,2), and derive an upper bound on the number of Fn(4;2,2).
Additionally, for any n greater than 2, we construct an Fn(4;2,2) that
cannot be refined to a latin hypercube, while each of its sub-Fnβ1(4;2,2)
can.
Keywords: frequency hypercube, frequency square, latin hypercube, testing
set, MDS cod