Triangular array read by rows. T(n,k) is the number of unlabeled functions on n nodes that have exactly k fixed points, n >= 0, 0 <= k <= n.
A217897
Triangular array read by rows. T(n,k) is the number of unlabeled functions on n nodes that have exactly k fixed points, n >= 0, 0 <= k <= n.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =1a(4) =1a(5) =1a(6) =2a(7) =3a(8) =1a(9) =1a(10) =6a(11) =7a(12) =4a(13) =1a(14) =1a(15) =13a(16) =19a(17) =9a(18) =4a(19) =1a(20) =1a(21) =40a(22) =47a(23) =27a(24) =10a(25) =4a(26) =1a(27) =1a(28) =100a(29) =130
External references
- oeis: A217897