%I #5 Aug 12 2016 07:04:20

%S 0,0,0,112,4912,265440,31924032,3170361984,597787563264,

%T 97379218955520,26489701471180800,6432079809975552000

%N Number of nX2 arrays containing 2 copies of 0..n-1 with no element plus any horizontal or vertical neighbor equal to n-1.

%C Column 2 of A265663.

%e Some solutions for n=4

%e ..0..1....3..1....0..1....3..1....2..0....1..3....2..2....3..2....0..1....2..3

%e ..2..0....2..0....0..1....1..0....3..2....1..3....0..0....3..2....1..0....0..1

%e ..3..1....2..0....2..3....0..2....1..0....0..2....1..1....1..0....3..2....1..3

%e ..2..3....3..1....2..3....2..3....3..1....0..2....3..3....0..1....3..2....0..2

%Y Cf. A265663.

%K nonn

%O 1,4

%A _R. H. Hardin_, Dec 12 2015