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

Author

Alois P. Heinz, Sep 04 2018

Keywords

• nonn

Links

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

Crossrefs

Column k=8 of A318757.

Programs

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);