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%I #11 Mar 04 2018 06:41:04
%S 60,246,1122,5118,23346,106494,485778,2215902,10107954,46107966,
%T 210323922,959403678,4376370546,19963045374,91062485778,415386338142,
%U 1894806719154,8643260919486,39426691159122,179846933956638
%N Number of (n+1) X 3 0..2 arrays with every 2 X 3 or 3 X 2 subblock having exactly three counterclockwise and three clockwise edge increases.
%C Column 2 of A206150.
%H R. H. Hardin, <a href="/A206144/b206144.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 5*a(n-1) - 2*a(n-2) for n > 3.
%F Empirical g.f.: 6*x*(2 - x)*(5 - 2*x) / (1 - 5*x + 2*x^2). - _Colin Barker_, Mar 04 2018
%e Some solutions for n=4:
%e ..0..1..0....0..1..0....1..2..1....1..2..0....0..1..2....2..1..0....2..0..2
%e ..1..2..1....2..0..1....0..1..2....2..1..2....1..0..1....0..2..1....1..2..0
%e ..2..0..2....0..1..0....1..0..1....0..2..0....2..1..2....1..0..2....2..0..1
%e ..0..2..1....2..0..1....0..1..2....1..0..2....0..2..0....2..1..0....0..2..0
%e ..1..0..2....0..2..0....1..0..1....0..1..0....2..0..1....0..2..1....2..0..1
%Y Cf. A206150.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 04 2012
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