A318797 Number of rooted trees with n nodes such that no more than three subtrees of the same size extend from the same node.

0, 1, 1, 2, 4, 8, 18, 43, 102, 250, 623, 1579, 4042, 10470, 27350, 72034, 190956, 509259, 1365271, 3677522, 9947145, 27007988, 73582758, 201103314, 551190098, 1514683667, 4172470962, 11519509386, 31869341642, 88337853393, 245301368188, 682307613945

Offset: 0

Author

Alois P. Heinz, Sep 03 2018

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..2158

Crossrefs

Column k=3 of A318753.

Programs

Maple

g:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
      binomial(g((i-1)$2)+j-1, j)*g(n-i*j, i-1), j=0..min(3, n/i))))
    end:
a:= n-> g((n-1)$2):
seq(a(n), n=0..40);