%I #3 Mar 31 2012 12:35:44
%S 1,70,31830,50395146,205822250572,1808558575291438,
%T 30242498188745996934
%N Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, down, up, down
%K nonn
%O 1,2
%A _R. H. Hardin_ May 10 2010