9535241

Appears in sequences

• Number of different quasi-orders (or topologies, or transitive digraphs) with n labeled elements.at n=7A000798
• Number of prime labeled topologies on n points.at n=5A028853
• Triangular array read by rows: T(n,k) is the number of transitive relations on {1,2,...,n} that have exactly k reflexive points, n>=0, 0<=k<=n.at n=35A245767
• Triangular 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=35A369776