%I #8 Dec 11 2015 11:56:16

%S 256,5228,88596,5048352,190349280,24408220320,10214794664928,

%T 3260439951760800,3545593194352716000,12774731370996169188000,

%U 35992614807976653175327200,345829680669306156240540420000

%N Number of (n+1) X (n+1) 0..3 arrays with every 2 X 3 or 3 X 2 subblock having exactly two counterclockwise and two clockwise edge increases.

%C Diagonal of A206118.

%H R. H. Hardin, <a href="/A206110/b206110.txt">Table of n, a(n) for n = 1..13</a>

%e Some solutions for n=4:

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 03 2012