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%I #2 Mar 31 2012 19:53:46
%S 21,94,544,3509,26799,223123
%N Number of permutations of length n with no consecutive triples i,...i+r,...i+2r for all r, and for all equal spacings d.
%C Here we count both the sequence 1,2,3 (r=1) as a progression in 1,2,3,0,4,5, (note d=1) and in 1,0,2,4,3,5 (here, d=2).
%e For n=4 there are 4!-a(4)=3 with some progression. These are (0,1,2,3), (1,2,3,0), and (3,0,1,2). Here for all the progressions, r=1 and d=1, hence this term is the same as a(4) in A002628.
%Y Cf. A002628, A174080, A174085, A174086, A174087.
%K nonn
%O 4,1
%A _Isaac Lambert_, Apr 20 2010