66200911138domain: NAppears in sequencesNumber of labeled partitions of (n,n) into pairs (i,j).at n=9A108459Number of partitions of the set {1,2,...,n} having no blocks that contain only odd entries.at n=18A124421Number of partitions of the set {1,2,...,n} having no blocks that contain only even entries.at n=18A124423