|
| |
|
|
A201702
|
|
Number of unlabeled 5-trees on n nodes
|
|
3
|
|
|
|
0, 0, 0, 0, 1, 1, 1, 2, 5, 15, 64, 342, 2321, 18578, 168287, 1656209, 17288336, 188006362, 2105867058, 24108331027, 280638347609, 3310098377912, 39462525169310, 474697793413215, 5754095507495584, 70216415130786725, 861924378411516159, 10636562125193377459
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,8
|
|
|
COMMENTS
|
A k-tree is recursively defined as follows: K_k is a k-tree and any k-tree on n+1 vertices is obtained by joining a vertex to a k-clique in a k-tree on n vertices.
|
|
|
REFERENCES
|
Miklos Bona, editor, Handbook of Enumerative Combinatorics, CRC Press, 2015, page 328.
|
|
|
LINKS
|
Table of n, a(n) for n=1..28.
Andrew Gainer-Dewar, Gamma-Species and the Enumeration of k-Trees, Electronic Journal of Combinatorics, Volume 19 (2012), #P45. - From N. J. A. Sloane, Dec 15 2012
|
|
|
CROSSREFS
|
Cf. A054581 (unlabeled 2-trees), A078792 (unlabeled 3-trees), A078793 (unlabeled 4-trees).
Sequence in context: A143872 A130756 A078793 * A202037 A322754 A224917
Adjacent sequences: A201699 A201700 A201701 * A201703 A201704 A201705
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Andrew R. Gainer, Dec 03 2011
|
|
|
STATUS
|
approved
|
| |
|
|
