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A318859 Number of rooted trees with n nodes such that two equals the maximal number of isomorphic subtrees extending from the same node. 3
0, 1, 1, 4, 9, 22, 54, 138, 346, 889, 2285, 5928, 15436, 40424, 106230, 280305, 741912, 1969816, 5243942, 13995807, 37439883, 100371907, 269623436, 725638613, 1956352468, 5283171593, 14289645110, 38707131195, 104995130162, 285184002486, 775586517781 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,4

LINKS

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

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))(2):

seq(a(n), n=2..32);

CROSSREFS

Column k=2 of A318758.

Sequence in context: A076859 A042833 A048654 * A318817 A122626 A135025

Adjacent sequences:  A318856 A318857 A318858 * A318860 A318861 A318862

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Sep 04 2018

STATUS

approved

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Last modified July 11 17:24 EDT 2020. Contains 335626 sequences. (Running on oeis4.)