A292212 Number of (unlabeled) rooted trees with n leaf nodes and without unary nodes or outdegrees larger than six.

0, 1, 1, 2, 5, 12, 33, 89, 258, 756, 2279, 6957, 21592, 67689, 214451, 684850, 2203384, 7133042, 23222003, 75971636, 249646198, 823597534, 2726859943, 9057797752, 30176758016, 100810029178, 337614951216, 1133292965615, 3812333876764, 12849946139206

Offset

0,4

Links

Alois P. Heinz, Table of n, a(n) for n = 0..1000

Index entries for sequences related to rooted trees

Maple

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

Crossrefs

Column k=6 of A292085.

Sequence in context: A084075 A209717 A000560 * A212823 A292213 A032124

Adjacent sequences: A292209 A292210 A292211 * A292213 A292214 A292215

Keyword

nonn

Author

Alois P. Heinz, Sep 11 2017

Status

approved