10199989800domain: NAppears in sequencesSecond-order reciprocal Stirling number (Fekete) a(n) = [[2n+2, n]]. The number of n-orbit permutations of a (2n+2)-set with at least 2 elements in each orbit. Also known as associated Stirling numbers of the first kind (e.g., Comtet).at n=7A000907