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A205249 Number of (n+1) X 3 0..1 arrays with the number of clockwise edge increases in every 2 X 2 subblock the same.

%I A205249 #8 Jun 11 2018 08:03:13
%S A205249 40,168,752,3416,15568,71000,323856,1477272,6738640,30738648,
%T A205249 140215952,639602456,2917580368,13308696920,60708323856,276924225432,
%U A205249 1263204479440,5762173946328,26284460772752,119897955971096,546920858309968
%N A205249 Number of (n+1) X 3 0..1 arrays with the number of clockwise edge increases in every 2 X 2 subblock the same.
%C A205249 Column 2 of A205255.
%H A205249 R. H. Hardin, <a href="/A205249/b205249.txt">Table of n, a(n) for n = 1..210</a>
%F A205249 Empirical: a(n) = 6*a(n-1) -7*a(n-2) +2*a(n-3).
%F A205249 Empirical g.f.: 8*x*(5 - 9*x + 3*x^2) / ((1 - x)*(1 - 5*x + 2*x^2)). - _Colin Barker_, Jun 11 2018
%e A205249 Some solutions for n=4:
%e A205249 ..1..1..1....1..0..1....0..0..1....1..1..1....1..1..1....1..1..0....1..1..1
%e A205249 ..0..0..1....0..1..0....0..1..1....0..1..0....1..0..1....0..0..0....1..1..1
%e A205249 ..1..1..1....1..0..1....1..1..0....0..1..0....1..1..1....0..1..1....1..1..1
%e A205249 ..0..1..0....0..1..0....1..0..0....0..1..1....1..0..1....0..1..0....1..1..1
%e A205249 ..1..1..1....1..0..1....0..0..1....1..1..0....1..0..0....0..0..0....1..1..1
%Y A205249 Cf. A205255.
%K A205249 nonn
%O A205249 1,1
%A A205249 _R. H. Hardin_, Jan 24 2012