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 A206745 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. 1

%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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Last modified February 1 12:28 EST 2023. Contains 359993 sequences. (Running on oeis4.)