OFFSET
0,2
LINKS
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 793
FORMULA
E.g.f.: log(-1/(-1+x))+log(-1/(-1+log(-1/(-1+x)))).
MAPLE
spec := [S, {B=Cycle(C), C=Cycle(Z), S=Union(C, B)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
encyclopedia(AT)pommard.inria.fr, Jan 25 2000
EXTENSIONS
More terms from Alois P. Heinz, Mar 16 2016
STATUS
approved