598444domain: NAppears in sequencesTotal number of preferential arrangements of 1, 2, ..., n things.at n=7A239914Number T(n,k) of tilings of a 5 X n rectangle with pentominoes of any shape and exactly k pentominoes of shape V; triangle T(n,k), n>=0, 0<=k<=max(0,n-2+delta_{n,3}), read by rows.at n=25A247709