{ "id": "2212.03694", "version": "v1", "published": "2022-12-07T15:10:47.000Z", "updated": "2022-12-07T15:10:47.000Z", "title": "An upper bound on the number of frequency hypercubes", "authors": [ "Denis S. Krotov", "Vladimir N. Potapov" ], "categories": [ "math.CO", "cs.DM" ], "abstract": "A frequency $n$-cube $F^n(q;l_0,...,l_{m-1})$ is an $n$-dimensional $q$-by-...-by-$q$ array, where $q = l_0+...+l_{m-1}$, filled by numbers $0,...,m-1$ with the property that each line contains exactly $l_i$ cells with symbol $i$, $i = 0,...,m-1$ (a line consists of $q$ cells of the array differing in one coordinate). The trivial upper bound on the number of frequency $n$-cubes is $m^{(q-1)^{n}}$. We improve that lower bound for $n>2$, replacing $q-1$ by a smaller value, by constructing a testing set of size $s^{n}$, $s