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%I #9 Jul 14 2018 05:20:29
%S 6,88,893,8217,73035,640495,5586791,48624987,422832951,3675525835,
%T 31945165919,277628591571,2412749978775,20967950350123,
%U 182220740086511,1583575892972451,13761939669663303,119597001511594267
%N Number of (n+1) X 2 0..2 arrays containing all values 0..2 with every 2 X 2 subblock having two or three distinct values, and new values 0..2 introduced in row major order.
%C Column 1 of A210012.
%H R. H. Hardin, <a href="/A210005/b210005.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 11*a(n-1) - 16*a(n-2) - 34*a(n-3) - 12*a(n-4).
%F Empirical g.f.: x*(3 + 2*x)*(2 + 6*x + 3*x^2) / ((1 - 3*x - 2*x^2)*(1 - 8*x - 6*x^2)). - _Colin Barker_, Jul 14 2018
%e Some solutions for n=4:
%e ..0..0....0..0....0..1....0..0....0..1....0..0....0..1....0..0....0..1....0..1
%e ..0..1....0..1....2..2....1..2....0..2....0..1....2..0....0..1....0..2....2..0
%e ..0..1....0..1....1..2....2..2....2..0....2..0....1..2....2..0....1..1....0..1
%e ..0..1....2..1....0..2....1..2....0..2....1..2....2..0....1..0....1..2....2..2
%e ..1..2....2..1....2..2....1..1....1..0....0..2....0..1....0..2....1..1....2..1
%Y Cf. A210012.
%K nonn
%O 1,1
%A _R. H. Hardin_, Mar 16 2012
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