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A244536
Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 7.
3
1, 0, 0, 0, 0, 0, 0, 7, 15, 16, 17, 18, 19, 20, 91, 253, 529, 852, 1225, 1651, 2133, 3493, 6931, 14095, 27156, 47648, 77297, 118031, 182462, 300441, 527398, 954712, 1722370, 3015910, 5074611, 8342271, 13730760, 23036563, 39558564, 68974240, 120541276
OFFSET
8,8
LINKS
MAPLE
b:= proc(n, t, k) option remember; `if`(n=0,
`if`(t in [0, k], 1, 0), `if`(t>n, 0, add(b(j-1, k$2)*
b(n-j, max(0, t-1), k), j=1..n)))
end:
a:= n-> b(n-1, 7$2) -b(n-1, 8$2):
seq(a(n), n=8..50);
CROSSREFS
Column k=7 of A244530.
Cf. A244461.
Sequence in context: A076401 A180114 A204740 * A237054 A216848 A065566
KEYWORD
nonn
AUTHOR
Joerg Arndt and Alois P. Heinz, Jun 29 2014
STATUS
approved