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%I
%S 256,1888,15680,139744,1289472,12105120,114566336,1088409696,
%T 10358308480,98658758944,940033716800,8958289929184,85376964317184,
%U 813714139891872,7755506295392192,73918257610362720,704522374079236480
%N Number of (n+1) X 2 0..3 arrays with every 2 X 3 or 3 X 2 subblock having an equal number of clockwise and counterclockwise edge increases.
%C Column 1 of A206752.
%H R. H. Hardin, <a href="/A206745/b206745.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 15*a(n-1) - 55*a(n-2) + 17*a(n-3) + 108*a(n-4) - 84*a(n-5).
%F Empirical g.f.: 32*x*(8 - 61*x + 45*x^2 + 126*x^3 - 126*x^4) / ((1 - x)*(1 - 3*x - 6*x^2)*(1 - 11*x + 14*x^2)). - _Colin Barker_, Jun 17 2018
%e Some solutions for n=4:
%e ..1..0....2..3....1..1....1..1....2..3....1..1....0..0....3..3....0..3....1..3
%e ..2..0....3..0....2..2....1..3....1..1....1..2....1..0....1..1....1..1....2..2
%e ..1..0....0..2....1..1....3..3....2..3....1..2....0..1....1..3....3..2....0..3
%e ..1..3....1..3....0..0....2..2....0..3....3..0....1..3....2..0....0..2....2..2
%e ..0..0....2..0....0..0....0..2....1..3....1..2....3..0....0..1....0..3....1..0
%Y Cf. A206752.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 12 2012
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