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A052864
E.g.f.: (log(1-x))^2/(1+log(1-x)).
1
0, 0, 2, 12, 82, 670, 6458, 72072, 915864, 13068768, 206998032, 3604604256, 68455569840, 1408152976464, 31191374639280, 740216664633984, 18736923967232256, 503916672279712896, 14349543617967990912
OFFSET
0,3
COMMENTS
Previous name was: A simple grammar.
FORMULA
E.g.f.: -log(-1/(-1+x))^2/(-1+log(-1/(-1+x)))
a(n) ~ n! * exp(n)/(exp(1)-1)^(n+1). - Vaclav Kotesovec, Oct 01 2013
MAPLE
spec := [S, {C=Cycle(Z), B=Sequence(C, 1 <= card), S=Prod(B, C)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
MATHEMATICA
CoefficientList[Series[(Log[1-x])^2/(1+Log[1-x]), {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Oct 01 2013 *)
CROSSREFS
Cf. A009122.
Sequence in context: A092850 A199420 A235348 * A355378 A136278 A130464
KEYWORD
easy,nonn
AUTHOR
encyclopedia(AT)pommard.inria.fr, Jan 25 2000
EXTENSIONS
New name using e.g.f., Vaclav Kotesovec, Oct 01 2013
STATUS
approved