%I #9 Jul 09 2018 14:56:24

%S 16,34,64,156,320,840,1792,4848,10496,28704,62464,171456,373760,

%T 1027200,2240512,6160128,13438976,36954624,80625664,221715456,

%U 483737600,1330268160,2902392832,7981559808,17414291456,47889260544,104485617664

%N 1/4 the number of (n+1) X 4 0..2 arrays with every 2 X 2 subblock having distinct edge sums.

%C Column 3 of A209382.

%H R. H. Hardin, <a href="/A209377/b209377.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 8*a(n-2) - 12*a(n-4).

%F Empirical g.f.: 2*x*(8 + 17*x - 32*x^2 - 58*x^3) / ((1 - 2*x^2)*(1 - 6*x^2)). - _Colin Barker_, Jul 09 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Cf. A209382.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 07 2012