910161domain: NAppears in sequencesNumber of connected labeled T_0-T_4-topologies with n points.at n=7A006059Triangular array read by rows. T(n,k) is the number of inequivalent (as defined below) transitive binary relations R on [n] such that |domain(R intersect R^(-1))| = k, n>=0, 0<=k<=n.at n=29A369776