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%I #5 Aug 12 2016 07:04:21
%S 1,0,8,104,6440,312960,36965712,3615441408,668391093888,
%T 108118788084480,29018593889026560,7014015968947706880
%N Number of nX2 arrays containing 2 copies of 0..n-1 with no element plus any vertical or antidiagonal neighbor equal to n-1.
%C Column 2 of A266042.
%e Some solutions for n=4
%e ..2..2....3..0....0..0....3..3....3..2....1..2....2..2....3..2....2..0....3..3
%e ..3..0....1..1....2..1....1..1....3..0....3..0....0..0....2..0....2..1....2..1
%e ..1..1....3..0....3..3....0..0....1..0....2..1....1..1....0..1....0..3....0..0
%e ..0..3....2..2....2..1....2..2....1..2....0..3....3..3....1..3....1..3....1..2
%Y Cf. A266042.
%K nonn
%O 1,3
%A _R. H. Hardin_, Dec 20 2015
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