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%I #9 Jun 13 2018 05:47:05
%S 423,1980,8004,33504,140802,591336,2482596,10425528,43778766,
%T 183827574,771932004,3241441338,13611219624,57155642244,240004267116,
%U 1007811633786,4231945805718,17770531374384,74620975427586,313344031580448
%N Number of (n+1) X 3 0..2 arrays with every 2 X 3 or 3 X 2 subblock having exactly two clockwise edge increases.
%C Column 2 of A205986.
%H R. H. Hardin, <a href="/A205980/b205980.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = a(n-1) + 7*a(n-2) + 26*a(n-3) + 5*a(n-4) - 12*a(n-6) - 4*a(n-7) for n>9.
%F Empirical g.f.: 3*x*(141 + 519*x + 1021*x^2 + 214*x^3 - 775*x^4 - 666*x^5 - 134*x^6 + 220*x^7 + 96*x^8) / (1 - x - 7*x^2 - 26*x^3 - 5*x^4 + 12*x^6 + 4*x^7). - _Colin Barker_, Jun 13 2018
%e Some solutions for n=4:
%e ..0..1..2....1..1..1....2..1..0....1..0..1....2..0..1....1..1..1....0..1..0
%e ..0..2..2....1..0..2....2..1..1....2..2..1....0..0..1....0..2..2....0..2..2
%e ..2..2..0....2..1..1....0..2..2....0..2..2....1..2..2....2..2..1....2..2..1
%e ..0..0..1....1..1..2....2..2..1....2..0..1....0..2..2....1..1..2....2..1..0
%e ..1..0..0....2..2..0....0..1..2....2..2..1....1..1..0....2..1..1....1..2..2
%Y Cf. A205986.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 02 2012