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A318861 Number of rooted trees with n nodes such that four equals the maximal number of isomorphic subtrees extending from the same node. 2
0, 1, 1, 3, 8, 23, 61, 167, 461, 1285, 3587, 10069, 28350, 80101, 226861, 644064, 1832113, 5221138, 14902620, 42597586, 121917123, 349343846, 1002080752, 2877234480, 8268665140, 23782254063, 68454314588, 197176382059, 568320901793, 1639070974728, 4729877188814 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,4

LINKS

Alois P. Heinz, Table of n, a(n) for n = 4..2143

MAPLE

h:= proc(n, m, t, k) option remember; `if`(m=0, binomial(n+t, t),

      `if`(n=0, 0, add(h(n-1, m-j, t+1, k), j=1..min(k, m))))

    end:

b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,

      add(b(n-i*j, i-1, k)*h(A(i, k), j, 0, k), j=0..n/i)))

    end:

A:= (n, k)-> `if`(n<2, n, b(n-1$2, k)):

a:= n-> (k-> A(n, k)-A(n, k-1))(4):

seq(a(n), n=4..34);

CROSSREFS

Column k=4 of A318758.

Sequence in context: A027244 A108457 A071618 * A318819 A146998 A261329

Adjacent sequences:  A318858 A318859 A318860 * A318862 A318863 A318864

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Sep 04 2018

STATUS

approved

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Last modified August 19 18:30 EDT 2022. Contains 356229 sequences. (Running on oeis4.)