Abstract
A collection of finite sets \(\{A_{1},A_{2},\ldots,A_{p}\}\) is said to be a double covering if each \(a\in\cup_{k=1}^{p}A_{k}\) is included in exactly two sets of the collection. For fixed integers \(l\) and \(p\) , let \(\mu_{l,p}\) be the number of equivalency classes of double coverings with \(\#(A_{k})=l\) , \(k=1,2,\ldots,p\) . We characterize the asymptotic behavior of the quantity \(\mu_{l,p}\) as \(p\to\infty\) . The results are applied to give an alternative approach to the Bonami–Kiener [1, 2] hypercontraction inequality.