|
| |
|
|
A052862
|
|
E.g.f.: ln(-1/(-2+exp(x)))*x
|
|
0
| |
|
|
0, 0, 2, 6, 24, 130, 900, 7574, 74928, 851274, 10916700, 155919742, 2453941512, 42188446898, 786563892660, 15805750451430, 340522975054176, 7829628493247002, 191363568551328780, 4954089147107164238
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
COMMENTS
| A simple grammar.
For n > 2, a(n) = (2*n + 4) * A000670(n-2). - Gerald McGarvey (gerald.mcgarvey(AT)comcast.net), Nov 01 2007
|
|
|
LINKS
| INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 830
|
|
|
MAPLE
| spec := [S, {B=Cycle(C), C=Set(Z, 1 <= card), S=Prod(Z, B)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
|
|
|
CROSSREFS
| Sequence in context: A144251 A201158 A191343 * A129101 A013068 A205182
Adjacent sequences: A052859 A052860 A052861 * A052863 A052864 A052865
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| encyclopedia(AT)pommard.inria.fr, Jan 25 2000
|
| |
|
|
