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Number of unlabeled mobiles with cycles of length at least 3.
1

%I #20 Feb 05 2018 22:02:57

%S 0,1,0,1,1,2,3,6,12,25,53,114,257,567,1294,2944,6790,15693,36598,

%T 85578,201299,474975,1125349,2674160,6374879,15236478,36510886,

%U 87688909,211061972,509015536,1229874162,2976713669,7216333477,17520731199,42599632645,103714603196

%N Number of unlabeled mobiles with cycles of length at least 3.

%H Robert Israel, <a href="/A052523/b052523.txt">Table of n, a(n) for n = 0..2234</a>

%H INRIA Algorithms Project, <a href="http://ecs.inria.fr/services/structure?nbr=91">Encyclopedia of Combinatorial Structures 91</a>

%p spec := [S,{S=Union(B,Z),B=Cycle(S,3 <= card)},unlabeled]: seq(combstruct[count](spec, size=n), n=0..20);

%K easy,nonn

%O 0,6

%A encyclopedia(AT)pommard.inria.fr, Jan 25 2000

%E Terms a(21) and beyond from b-file by _Andrew Howroyd_, Feb 05 2018