Triangular array read by rows. T(n,k) is the number of binary relations R on [n] such that the unique idempotent in {R^i:i>=1} contains exactly k non-arcless strongly connected components, n>=0, 0<=k<=n.
A370464
Triangular array read by rows. T(n,k) is the number of binary relations R on [n] such that the unique idempotent in {R^i:i>=1} contains exactly k non-arcless strongly connected components, n>=0, 0<=k<=n.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =3a(4) =9a(5) =4a(6) =25a(7) =277a(8) =162a(9) =48a(10) =543a(11) =38409a(12) =18136a(13) =6912a(14) =1536a(15) =29281a(16) =23169481a(17) =7195590a(18) =2346000a(19) =691200a(20) =122880
External references
- oeis: A370464