283944domain: NAppears in sequencesGeneralized Stirling numbers of second kind.at n=7A000558Matrix square of Stirling2 triangle A008277: 2-levels set partitions of [n] into k first-level subsets.at n=37A039810Triangle of generalized Stirling numbers of 2nd kind.at n=43A046817Square of the Stirling2 matrix A048993.at n=47A130191