%I #10 Oct 27 2014 10:21:37
%S 1,1,0,0,0,0,0,0,2,72,1496,25384,399848,6231544,99133496,1634227958,
%T 28120703888,506599465896,9562489659952,189055933191880,
%U 3911226769004280
%N Number of permutations of 1..n such that |p(i)-p(i-1)|>= 4 for i>1.
%K nonn
%O 0,9
%A _R. H. Hardin_, Aug 03 2010
%E a(0), a(19)-a(20) from _Alois P. Heinz_, Oct 27 2014