A292232 Number of (unlabeled) rooted trees with n leaf nodes and without unary nodes such that the maximum of the node outdegrees equals six.

1, 2, 7, 23, 78, 261, 887, 3008, 10268, 35112, 120445, 413979, 1425919, 4919635, 17000553, 58828575, 203826882, 707008418, 2454916048, 8532126320, 29679297122, 103322632386, 359962092302, 1254914172463, 4377704183644, 15280415561913, 53365850603107

Offset

6,2

Links

Alois P. Heinz, Table of n, a(n) for n = 6..1000

Index entries for sequences related to rooted trees

Maple

b:= proc(n, i, v, k) option remember; `if`(n=0,
      `if`(v=0, 1, 0), `if`(i<1 or v<1 or n<v, 0,
      `if`(v=n, 1, add(binomial(A(i, k)+j-1, j)*
       b(n-i*j, i-1, v-j, k), j=0..min(n/i, v)))))
    end:
A:= proc(n, k) option remember; `if`(n<2, n,
      add(b(n, n+1-j, j, k), j=2..min(n, k)))
    end:
a:= n-> A(n, 6)-A(n, 5):
seq(a(n), n=6..35);

Crossrefs

Column k=6 of A292086.

Sequence in context: A067324 A047062 A292231 * A292233 A292234 A292235

Adjacent sequences: A292229 A292230 A292231 * A292233 A292234 A292235

Keyword

nonn

Author

Alois P. Heinz, Sep 12 2017

Status

approved