%I
%S 0,2,12,504,22320,1521360,140394240,17034433920,2627788262400,
%T 502511002156800,116684130094963200,32342603041381248000
%N Number of nX2 arrays containing 2 copies of 0..n1 with no equal horizontal or vertical neighbors.
%C Column 2 of A264954.
%e Some solutions for n=4
%e ..1..2....2..0....2..3....2..1....3..1....0..3....1..2....3..2....0..1....3..1
%e ..0..3....3..1....0..1....0..2....0..3....2..1....2..0....0..1....2..3....1..3
%e ..3..1....0..2....1..3....3..0....2..0....1..3....0..3....2..3....1..0....2..0
%e ..0..2....3..1....2..0....1..3....1..2....0..2....3..1....0..1....3..2....0..2
%Y Cf. A264954.
%K nonn
%O 1,2
%A _R. H. Hardin_, Nov 29 2015
