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A318854
Number of rooted trees with n nodes such that no more than seven isomorphic subtrees extend from the same node.
2
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
0,4
LINKS
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);
CROSSREFS
Column k=7 of A318757.
Sequence in context: A145545 A182378 A318801 * A255638 A215971 A034825
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 04 2018
STATUS
approved