  Given positive integers $n,k$ with $k\leq n$, we consider the number of ways
of choosing $k$ subsets of $\{1,\ldots,n\}$ in such a way that the union of
these subsets gives $\{1,\ldots,n\}$ and they are not subsets of each other. We
refer to such choices of sets as constructive $k$-covers and provide a
semi-analytic summation formula to calculate the exact number of constructive
$k$-covers of $\{1,\ldots,n\}$. Each term in the summation is the product of a
new variant of Stirling numbers of the second kind, referred to as integrated
Stirling numbers, and the cardinality of a certain set which we calculate by an
optimization-based procedure with no-good cuts for binary variables.
