Triangular array T(n,k) read by rows, giving number of labeled free trees such that the root is smaller than all its children, with respect to the number n of vertices and to the number k of decreasing edges.
A071208
Triangular array T(n,k) read by rows, giving number of labeled free trees such that the root is smaller than all its children, with respect to the number n of vertices and to the number k of decreasing edges.
Terms
- a(0) =1a(1) =2a(2) =2a(3) =6a(4) =15a(5) =6a(6) =24a(7) =104a(8) =104a(9) =24a(10) =120a(11) =770a(12) =1345a(13) =770a(14) =120a(15) =720a(16) =6264a(17) =16344a(18) =16344a(19) =6264a(20) =720a(21) =5040a(22) =56196a(23) =200452a(24) =300167a(25) =200452a(26) =56196a(27) =5040a(28) =40320a(29) =554112
External references
- oeis: A071208