%I #6 Nov 02 2013 18:08:15
%S 1,46,11722,9659528,19879855515,86520373465693,709390751745167960,
%T 10064485309871565223880
%N Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, up.
%K nonn
%O 1,2
%A _R. H. Hardin_, May 10 2010
%E a(8) from _Alois P. Heinz_, Nov 02 2013
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