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%I #5 Oct 22 2013 18:45:12
%S 1,10,238,10588,779092,87126856,13960372312,3064747884400,
%T 890409817619536,332982388081862176
%N Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down.
%K nonn
%O 1,2
%A _R. H. Hardin_, May 10 2010
%E a(10) from _Alois P. Heinz_, Oct 22 2013