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%I #8 Jul 13 2018 05:48:20
%S 34,302,2721,25505,244208,2377378,23398105,231987361,2311229272,
%T 23098641162,231319042937,2319549963665,23278778523264,
%U 233749081336914,2347950341283193,23589750833899361,237038455370387400
%N Number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock having two distinct values, and new values 0..3 introduced in row major order.
%C Column 2 of A209814.
%H R. H. Hardin, <a href="/A209808/b209808.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 17*a(n-1) - 68*a(n-2) - 56*a(n-3) + 397*a(n-4) - 181*a(n-5) - 264*a(n-6) + 108*a(n-7).
%F Empirical g.f.: x*(34 - 276*x - 101*x^2 + 1688*x^3 - 935*x^4 - 1182*x^5 + 504*x^6) / ((1 - 6*x - 3*x^2 + 2*x^3)*(1 - 11*x + 5*x^2 + 51*x^3 - 54*x^4)). - _Colin Barker_, Jul 13 2018
%e Some solutions for n=4:
%e ..0..0..0....0..0..1....0..0..0....0..1..1....0..0..0....0..1..1....0..1..0
%e ..1..1..1....1..0..0....0..1..0....0..0..1....0..1..1....0..0..0....0..1..0
%e ..0..0..0....1..0..1....0..1..0....1..1..0....1..0..1....0..1..1....0..1..0
%e ..1..0..1....0..0..0....1..1..0....0..0..0....1..0..0....1..1..2....1..0..0
%e ..0..0..0....0..1..1....2..1..0....0..1..0....1..0..1....1..2..1....0..1..0
%Y Cf. A209814.
%K nonn
%O 1,1
%A _R. H. Hardin_, Mar 13 2012
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