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%I #4 Mar 31 2012 19:53:46
%S 20,100,600,4244,34264,311424,3143912,34833964,420917638,5513592091,
%T 77715460917
%N Number of circular permutations of length n with no consecutive triples i,i+2,i+4 or i,i-2,i-4.
%C Circular permutations are permutations whose indices are from the ring of integers modulo n.
%e For n=5 there are (5-1)!-a(5)=4 circular permutations with i,i+2,i+4 or i,i-2,i-4 triples. They are (0,2,4,1,3), (0,2,4,3,1), (0,1,3,4,2), and (0,3,1,4,2).
%Y Cf. A165964, A174076, A174077, A174079.
%K nonn
%O 5,1
%A _Isaac Lambert_, Mar 10 2010
%E a(10)-a(15) from _Donovan Johnson_, Sep 24 2010
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