%I #6 Nov 23 2014 17:17:39
%S 16,32,128,400,1344,4416,14608,48224,159296,526096,1737600,5738880,
%T 18954256,62601632,206759168,682879120,2255396544,7449068736,
%U 24602602768,81256877024,268373233856,886376578576,2927502969600,9668885487360
%N Number of (n+1)X(3+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally, diagonally or antidiagonally, with no adjacent elements equal
%C Column 3 of A232515
%H R. H. Hardin, <a href="/A232510/b232510.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) +4*a(n-2) +a(n-3).
%F Empirical: G.f.: -16*x / ( (1+x)*(x^2+3*x-1) ), which means a(n) is 16 times 1, 2, 8, 25, 84, 276 and so on with pairs of adjacent numbers summing to A006190. - _R. J. Mathar_, Nov 23 2014
%e Some solutions for n=7
%e ..0..1..2..1....0..1..0..1....0..1..0..1....0..1..0..1....2..1..0..1
%e ..0..1..0..1....2..1..2..1....2..1..2..1....2..1..2..1....0..1..2..1
%e ..2..1..2..1....2..1..2..1....2..1..2..1....0..1..0..1....2..1..0..1
%e ..2..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1....2..1..2..1
%e ..2..1..2..1....2..1..2..1....2..1..0..1....2..1..2..1....0..1..2..1
%e ..0..1..0..1....0..1..0..1....0..1..2..1....0..1..2..1....0..1..0..1
%e ..2..1..2..1....2..1..0..1....0..1..2..1....0..1..0..1....0..1..2..1
%e ..0..1..0..1....2..1..2..1....2..1..0..1....0..1..2..1....0..1..0..1
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 25 2013