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%I #8 Jul 15 2018 12:03:46
%S 78,2520,80496,2574592,82334080,2633043200,84204544256,2692856218368,
%T 86117376515328,2754028420465408,88073659990146304,
%U 2816590245285823232,90074383313881529600,2880573254472884060928,92120556023893690612992
%N Number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock having three or four distinct values, and new values 0..3 introduced in row major order.
%C Column 2 of A210413.
%H R. H. Hardin, <a href="/A210407/b210407.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 31*a(n-1) + 40*a(n-2) - 280*a(n-3) + 96*a(n-4).
%F Empirical g.f.: 2*x*(39 + 51*x - 372*x^2 + 128*x^3) / (1 - 31*x - 40*x^2 + 280*x^3 - 96*x^4). - _Colin Barker_, Jul 15 2018
%e Some solutions for n=4:
%e ..0..0..1....0..0..0....0..0..0....0..1..0....0..0..0....0..0..0....0..0..0
%e ..1..2..0....1..2..1....1..2..3....2..1..2....1..2..3....1..2..1....1..2..1
%e ..0..1..2....3..2..3....0..1..2....1..0..3....3..2..1....2..3..0....1..0..0
%e ..0..3..3....1..3..0....1..3..0....2..3..1....1..0..3....1..3..1....1..2..3
%e ..0..1..0....2..1..1....0..1..3....0..0..2....3..0..1....3..0..1....3..0..3
%Y Cf. A210413.
%K nonn
%O 1,1
%A _R. H. Hardin_, Mar 21 2012
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