A318854 Number of rooted trees with n nodes such that no more than seven isomorphic subtrees extend from the same node.

0, 1, 1, 2, 4, 9, 20, 48, 115, 285, 717, 1837, 4753, 12451, 32878, 87549, 234654, 632813, 1715444, 4672539, 12780498, 35091807, 96684475, 267223388, 740690724, 2058468456, 5734614714, 16011714554, 44799497491, 125587597952, 352696620393, 992168348175

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=7 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(7, 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);