A174081 - OEIS

%I #2 Mar 31 2012 19:53:46

%S 16,40,300,1764,17056,118908

%N Number of permutations of length n with no consecutive triples i,i+d,i+2d (mod n) for all d.

%e For n=4, there are 4!-a(4)=8 permutations with some consecutive triple i,i+d,i+2d (mod 4). Here only d=1 and d=3 works, and the permutations are (0,1,2,3), (1,2,3,0), (2,3,0,1), (3,0,1,2), (0,3,2,1), (3,2,1,0), (2,1,0,3), and (1,0,3,2)

%Y Cf. A095816, A174073, A174080, A174082, A174083.

%K nonn

%O 4,1

%A _Isaac Lambert_, Mar 15 2010