%I #6 Nov 02 2013 16:39:42
%S 1,70,25446,29416791,83400344760,492319974701196,5405431813676888595,
%T 101632942861784833336188
%N Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, down.
%K nonn
%O 1,2
%A _R. H. Hardin_, May 10 2010
%E a(8) from _Alois P. Heinz_, Nov 02 2013