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.

A245767

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.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =3a(4) =6a(5) =4a(6) =19a(7) =57a(8) =66a(9) =29a(10) =219a(11) =876a(12) =1428a(13) =1116a(14) =355a(15) =4231a(16) =21155a(17) =44500a(18) =49070a(19) =28405a(20) =6942a(21) =130023a(22) =780138a(23) =2013810a(24) =2858700a(25) =2354415a(26) =1068576a(27) =209527a(28) =6129859a(29) =42909013

External references