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A244707
Number of n-node unlabeled rooted trees with thinning limbs and root outdegree (branching factor) 6.
2
1, 1, 3, 6, 15, 31, 74, 157, 359, 786, 1766, 3895, 8710, 19287, 42987, 95437, 212468, 472204, 1050940, 2337221, 5201558, 11573156, 25759514, 57332239, 127633669, 284148877, 632704464, 1408925270, 3137861761, 6989057709, 15568767849, 34684141315, 77277619879
OFFSET
7,3
COMMENTS
In a rooted tree with thinning limbs the outdegree of a parent node is larger than or equal to the outdegree of any of its child nodes.
LINKS
MAPLE
b:= proc(n, i, h, v) option remember; `if`(n=0,
`if`(v=0, 1, 0), `if`(i<1 or v<1 or n<v, 0,
`if`(n=v, 1, add(binomial(A(i, min(i-1, h))+j-1, j)
*b(n-i*j, i-1, h, v-j), j=0..min(n/i, v)))))
end:
A:= proc(n, k) option remember;
`if`(n<2, n, add(b(n-1$2, j$2), j=1..min(k, n-1)))
end:
a:= n-> b(n-1$2, 6$2):
seq(a(n), n=7..50);
CROSSREFS
Column k=6 of A244657.
Sequence in context: A293732 A117161 A319765 * A244708 A244709 A244710
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jul 04 2014
STATUS
approved