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A318860 Number of rooted trees with n nodes such that three equals the maximal number of isomorphic subtrees extending from the same node. 2
0, 1, 1, 3, 9, 23, 60, 164, 443, 1209, 3319, 9150, 25326, 70335, 195870, 546823, 1529935, 4288662, 12042447, 33866604, 95373852, 268925258, 759157224, 2145298117, 6068251826, 17180172176, 48680092670, 138041661905, 391725281701, 1112360700816, 3160707529077 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,4

LINKS

Alois P. Heinz, Table of n, a(n) for n = 3..2158

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))(3):

seq(a(n), n=3..33);

CROSSREFS

Column k=3 of A318758.

Sequence in context: A309301 A323798 A180488 * A318818 A026599 A061647

Adjacent sequences:  A318857 A318858 A318859 * A318861 A318862 A318863

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Sep 04 2018

STATUS

approved

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Last modified August 17 02:42 EDT 2022. Contains 356180 sequences. (Running on oeis4.)