A318855 Number of rooted trees with n nodes such that no more than eight isomorphic subtrees extend from the same node.

0, 1, 1, 2, 4, 9, 20, 48, 115, 286, 718, 1840, 4761, 12473, 32938, 87716, 235119, 634120, 1719126, 4682961, 12810091, 35176098, 96925138, 267912073, 742665243, 2064139425, 5750927105, 16058701943, 44935012272, 125978876163, 353827545217, 995440198833

Offset

0,4

Links

Alois P. Heinz, Table of n, a(n) for n = 0..2136

Maple

h:= proc(n, m, t) option remember; `if`(m=0, binomial(n+t, t),
      `if`(n=0, 0, add(h(n-1, m-j, t+1), j=1..min(8, m))))
    end:
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
      add(b(n-i*j, i-1)*h(a(i), j, 0), j=0..n/i)))
    end:
a:= n-> `if`(n<2, n, b(n-1$2)):
seq(a(n), n=0..35);

Crossrefs

Column k=8 of A318757.

Sequence in context: A145546 A292553 A318802 * A255639 A216062 A034826

Adjacent sequences: A318852 A318853 A318854 * A318856 A318857 A318858

Keyword

nonn

Author

Alois P. Heinz, Sep 04 2018

Status

approved