|
|
A318904
|
|
Number of n-node rooted trees in which eight equals the maximal number of nodes in paths starting at a leaf and ending at the first branching node or at the root.
|
|
2
|
|
|
1, 1, 3, 8, 22, 60, 167, 465, 1305, 3677, 10407, 29545, 84137, 240180, 687169, 1969805, 5656352, 16267296, 46848655, 135089324, 389976522, 1126951399, 3259744738, 9437132452, 27342937037, 79281644947, 230037790501, 667888276997, 1940294941620, 5639933760363
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
8,3
|
|
LINKS
|
|
|
MAPLE
|
g:= proc(n, k) option remember; `if`(n=0, 1, add(add(d*(g(d-1, k)-
`if`(d=k, 1, 0)), d=numtheory[divisors](j))*g(n-j, k), j=1..n)/n)
end:
a:= n-> (k-> g(n-1, k) -g(n-1, k-1))(8):
seq(a(n), n=8..38);
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|