On the Structure of Small Strength-$2$ Covering Arrays

Janne I. Kokkala, Karen Meagher, Reza Naserasr +3

A covering array $\mathrm{CA}(\mathrm{N};\mathrm{t},\mathrm{k},\mathrm{v})$ of strength $t$ is an $N\times k$ array of symbols from an alphabet of size $v$ such that in every $N\times t$ subarray, every $t$-tuple occur…