%I #8 Jan 25 2016 15:51:39
%S 1,1,20,1680,354624,151213748,114062310060,139028830444866,
%T 256400413791435360,680598969845995094212,2500271405904975564019712
%N Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, down, down.
%Y Cf. A014606.
%K nonn
%O 0,3
%A _R. H. Hardin_, May 10 2010
%E a(9)-a(10) from _Alois P. Heinz_, Nov 02 2013