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A204071 Number of (n+1) X 4 0..2 arrays with every 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order.

%I A204071 #8 Jun 06 2018 05:40:57
%S A204071 188,2882,45056,706454,11081828,173848010,2727300008,42785526110,
%T A204071 671213931980,10529919897938,165192062569424,2591512360153766,
%U A204071 40655320900906676,637795575671145050,10005657004627715960
%N A204071 Number of (n+1) X 4 0..2 arrays with every 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order.
%C A204071 Column 3 of A204076.
%H A204071 R. H. Hardin, <a href="/A204071/b204071.txt">Table of n, a(n) for n = 1..210</a>
%F A204071 Empirical: a(n) = 20*a(n-1) - 73*a(n-2) + 86*a(n-3) - 32*a(n-4).
%F A204071 Empirical g.f.: 2*x*(94 - 439*x + 570*x^2 - 224*x^3) / ((1 - x)*(1 - 19*x + 54*x^2 - 32*x^3)). - _Colin Barker_, Jun 06 2018
%e A204071 Some solutions for n=4:
%e A204071 ..0..1..0..2....0..0..0..0....0..0..0..1....0..0..1..2....0..0..0..1
%e A204071 ..2..0..0..0....0..1..0..1....2..0..1..1....0..2..0..1....2..0..1..0
%e A204071 ..2..2..0..1....1..2..1..2....2..2..0..1....2..1..2..0....0..2..0..1
%e A204071 ..2..1..2..0....1..1..2..2....1..2..2..0....2..2..1..2....2..0..0..0
%e A204071 ..1..2..2..2....1..2..1..2....1..1..2..2....0..2..2..2....2..2..0..1
%Y A204071 Cf. A204076.
%K A204071 nonn
%O A204071 1,1
%A A204071 _R. H. Hardin_, Jan 10 2012