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%I #8 Dec 26 2018 08:59:49
%S 32,54,140,242,312,722,1388,1974,3824,7718,12060,21218,42344,71394,
%T 121052,233030,412608,698390,1295276,2349522,4031384,7276274,13283916,
%U 23174102,41199248,74964486,132548156,234319298,423455688,755086082
%N Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 or 00000011.
%H R. H. Hardin, <a href="/A259716/b259716.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 4*a(n-3) + 3*a(n-4).
%F Empirical g.f.: 2*x*(16 + 27*x + 70*x^2 + 57*x^3) / (1 - 4*x^3 - 3*x^4). - _Colin Barker_, Dec 26 2018
%e Some solutions for n=4:
%e ..1..1..0....0..0..1....0..0..0....0..1..1....0..0..0....1..0..0....0..0..1
%e ..0..1..0....0..0..1....0..0..1....0..1..0....0..0..0....0..1..0....0..1..0
%e ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..1....0..0..0....0..0..0
%e ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0
%e ..1..0..0....1..1..0....0..1..0....0..1..0....0..0..0....1..0..0....0..1..0
%e ..1..0..0....0..0..0....1..0..0....0..1..0....1..1..0....0..0..0....0..1..0
%Y Column 1 of A259723.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jul 03 2015
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