%I #5 Aug 12 2016 07:04:21
%S 1,0,2,38,1197,64497,4975742,519665920,70425165645,12012958306121,
%T 2518082525423953,636165450001831755
%N Number of nX2 arrays containing 2 copies of 0..n-1 with no element 1 greater than its north or northeast neighbor modulo n and the upper left element equal to 0.
%C Column 2 of A266599.
%e Some solutions for n=4
%e ..0..2....0..0....0..1....0..1....0..3....0..1....0..1....0..3....0..2....0..1
%e ..2..1....2..3....3..0....3..3....2..2....3..0....3..1....2..2....0..1....0..3
%e ..1..0....1..3....3..2....2..2....1..1....2..3....3..0....1..1....3..3....3..2
%e ..3..3....1..2....1..2....1..0....0..3....2..1....2..2....3..0....1..2....2..1
%Y Cf. A266599.
%K nonn
%O 1,3
%A _R. H. Hardin_, Jan 01 2016