A177663 - OEIS

%I #3 Mar 31 2012 12:35:44

%S 1,70,34052,59177576,268686190790,2643357374211756,

%T 49707855255794171208

%N Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, down, up, up, down

%K nonn

%O 1,2

%A _R. H. Hardin_ May 10 2010