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A318856
Number of rooted trees with n nodes such that no more than nine isomorphic subtrees extend from the same node.
2
0, 1, 1, 2, 4, 9, 20, 48, 115, 286, 719, 1841, 4764, 12481, 32960, 87776, 235286, 634585, 1720432, 4686643, 12820514, 35205695, 97009447, 268152808, 743354184, 2066114828, 5756601016, 16075023964, 44982030666, 126114489722, 354219135234, 996572101259
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(9, 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=9 of A318757.
Sequence in context: A145547 A292554 A318803 * A255640 A216403 A145548
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 04 2018
STATUS
approved