A318817 Number of rooted trees with n nodes such that two equals the maximal number of subtrees of the same size extending from the same node.

0, 1, 1, 4, 9, 22, 54, 139, 346, 892, 2290, 5945, 15465, 40527, 106308, 280629, 742107, 1969394, 5239322, 13980900, 37368692, 100157418, 268900827, 723400570, 1949440608, 5262932344, 14227803491, 38529294292, 104473993774, 283672750693, 771229441388

Offset

2,4

Links

Alois P. Heinz, Table of n, a(n) for n = 2..2213

Maple

g:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
      binomial(g(i-1$2, k)+j-1, j)*g(n-i*j, i-1, k), j=0..min(k, n/i))))
    end:
a:= n-> (k-> g(n-1$2, k) -g(n-1$2, k-1))(2):
seq(a(n), n=2..32);

Crossrefs

Column k=2 of A318754.

Sequence in context: A042833 A048654 A318859 * A122626 A135025 A231213

Adjacent sequences: A318814 A318815 A318816 * A318818 A318819 A318820

Keyword

nonn

Author

Alois P. Heinz, Sep 04 2018

Status

approved