Triangle read by rows: T(n,h) = number of functions f:{1,2,...,n}->{1,2,...,n} such that |Image(f)|=h; h=1,2,...,n, n=1,2,3,... . Essentially A090657, but without zeros.
A101817
Triangle read by rows: T(n,h) = number of functions f:{1,2,...,n}->{1,2,...,n} such that |Image(f)|=h; h=1,2,...,n, n=1,2,3,... . Essentially A090657, but without zeros.
Terms
- a(0) =1a(1) =2a(2) =2a(3) =3a(4) =18a(5) =6a(6) =4a(7) =84a(8) =144a(9) =24a(10) =5a(11) =300a(12) =1500a(13) =1200a(14) =120a(15) =6a(16) =930a(17) =10800a(18) =23400a(19) =10800a(20) =720a(21) =7a(22) =2646a(23) =63210a(24) =294000a(25) =352800a(26) =105840a(27) =5040a(28) =8a(29) =7112
External references
- oeis: A101817