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A244535
Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 6.
3
1, 0, 0, 0, 0, 0, 6, 13, 14, 15, 16, 17, 69, 190, 400, 651, 946, 1288, 2186, 4425, 9126, 17811, 31654, 51997, 85841, 149916, 276056, 518089, 960466, 1718395, 3006963, 5269873, 9392821, 17032418, 31098198, 56432687, 101350402, 180978701, 323731177, 582832779
OFFSET
7,7
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, 6$2) -b(n-1, 7$2):
seq(a(n), n=7..50);
CROSSREFS
Column k=6 of A244530.
Cf. A244460.
Sequence in context: A090324 A106623 A115010 * A066826 A031113 A112610
KEYWORD
nonn
AUTHOR
Joerg Arndt and Alois P. Heinz, Jun 29 2014
STATUS
approved