|
| |
|
|
A052809
|
|
A simple grammar: number of cycles of cycles.
|
|
0
| |
|
|
0, 0, 2, 6, 28, 175, 1368, 12838, 140656, 1762794, 24878320, 390495336, 6748280064, 127324033824, 2604355096224, 57404425654080, 1356401049662208, 34202807058719568, 916723959720053760
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
LINKS
| INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 771
|
|
|
FORMULA
| E.g.f.: ln(-1/(-1+ln(-1/(-1+x))))*x
|
|
|
MAPLE
| spec := [S, {B=Cycle(C), C=Cycle(Z), S=Prod(B, Z)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
|
|
|
CROSSREFS
| Sequence in context: A156626 A088501 A140092 * A136631 A002435 A104018
Adjacent sequences: A052806 A052807 A052808 * A052810 A052811 A052812
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| encyclopedia(AT)pommard.inria.fr, Jan 25 2000
|
| |
|
|
