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%I #10 Jun 14 2018 08:05:31
%S 124,1012,8304,68180,559788,4596072,37735460,309822148,2543754976,
%T 20885173732,171475038268,1407873792488,11559167069396,94905057577684,
%U 779205793959872,6397569158457620,52526420432849004,431261433077432552
%N Number of (n+1) X 2 0..3 arrays with the number of clockwise edge increases in every 2 X 2 subblock equal to two.
%C Column 1 of A206197.
%H R. H. Hardin, <a href="/A206190/b206190.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 9*a(n-1) - 7*a(n-2) + 4*a(n-3) + 2*a(n-4).
%F Empirical g.f.: 4*x*(31 - 26*x + 16*x^2 + 8*x^3) / (1 - 9*x + 7*x^2 - 4*x^3 - 2*x^4). - _Colin Barker_, Jun 14 2018
%e Some solutions for n=4:
%e 2 0 1 1 3 3 2 3 0 1 3 0 2 3 3 3 2 0 0 1
%e 1 0 3 2 1 0 3 0 0 2 1 0 0 1 1 0 2 1 0 2
%e 0 1 0 3 2 1 1 2 1 3 0 3 2 0 2 1 1 2 3 2
%e 0 3 1 0 1 3 3 2 3 0 2 0 0 1 0 2 0 1 1 3
%e 1 0 2 1 1 0 0 3 0 3 1 1 3 0 0 3 1 2 0 3
%Y Cf. A206197.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 04 2012
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