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%I #9 Jul 15 2018 06:53:23
%S 1,51,744,9042,103752,1165620,12988416,144259560,1600182816,
%T 17740623696,196642606464,2179465613472,24155044021632,
%U 267707038144320,2966944305186816,32881987112668800,364423467992173056
%N Number of (n+1) X 2 0..3 arrays containing all values 0..3 with every 2 X 2 subblock having three or four distinct values, and new values 0..3 introduced in row major order.
%C Column 1 of A210183.
%H R. H. Hardin, <a href="/A210176/b210176.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 14*a(n-1) - 26*a(n-2) - 68*a(n-3) - 24*a(n-4).
%F Empirical g.f.: x*(1 + x)*(1 + 36*x + 20*x^2) / ((1 - 4*x - 2*x^2)*(1 - 10*x - 12*x^2)). - _Colin Barker_, Jul 15 2018
%e Some solutions for n=4:
%e ..0..0....0..0....0..1....0..0....0..0....0..0....0..0....0..1....0..0....0..0
%e ..1..2....1..2....2..3....1..2....1..2....1..2....1..2....2..0....1..2....1..2
%e ..0..1....3..1....2..0....1..3....0..1....3..1....1..3....0..1....3..2....1..3
%e ..1..2....2..1....1..1....0..3....1..2....1..2....3..2....3..0....0..1....2..1
%e ..3..3....0..1....2..3....3..1....0..3....0..1....0..0....2..0....0..2....2..3
%Y Cf. A210183.
%K nonn
%O 1,2
%A _R. H. Hardin_, Mar 18 2012
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