Triangular array read by rows: T(n,k) is the number of functions f:{1,2,...,n}->{1,2,...,n} with a height of k; n>=1, 0<=k<=n-1.
A216242
Triangular array read by rows: T(n,k) is the number of functions f:{1,2,...,n}->{1,2,...,n} with a height of k; n>=1, 0<=k<=n-1.
Terms
- a(0) =1a(1) =2a(2) =2a(3) =6a(4) =15a(5) =6a(6) =24a(7) =124a(8) =84a(9) =24a(10) =120a(11) =1185a(12) =1160a(13) =540a(14) =120a(15) =720a(16) =13086a(17) =17610a(18) =10560a(19) =3960a(20) =720a(21) =5040a(22) =165361a(23) =296772a(24) =214410a(25) =104160a(26) =32760a(27) =5040a(28) =40320a(29) =2363320
External references
- oeis: A216242