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A318797
Number of rooted trees with n nodes such that no more than three subtrees of the same size extend from the same node.
2
0, 1, 1, 2, 4, 8, 18, 43, 102, 250, 623, 1579, 4042, 10470, 27350, 72034, 190956, 509259, 1365271, 3677522, 9947145, 27007988, 73582758, 201103314, 551190098, 1514683667, 4172470962, 11519509386, 31869341642, 88337853393, 245301368188, 682307613945
OFFSET
0,4
LINKS
MAPLE
g:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
binomial(g((i-1)$2)+j-1, j)*g(n-i*j, i-1), j=0..min(3, n/i))))
end:
a:= n-> g((n-1)$2):
seq(a(n), n=0..40);
CROSSREFS
Column k=3 of A318753.
Sequence in context: A024428 A330269 A049075 * A318850 A052327 A059221
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 03 2018
STATUS
approved