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%I #10 Sep 26 2018 15:43:35
%S 2,9,40,182,808,3688,16368,74728,331648,1514160,6719936,30680320,
%T 136161152,621652928,2758934016,12596099456,55902265856,255225567744,
%U 1132706802688,5171449356800,22951211032576,104785303002112
%N Number of (n+1) X (2+1) black-square subarrays of 0..2 arrays with no element equal to a strict majority of its diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order.
%H R. H. Hardin, <a href="/A231134/b231134.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 22*a(n-2) - 36*a(n-4) + 16*a(n-6).
%F Empirical g.f.: x*(2 + 9*x - 4*x^2 - 16*x^3 + 8*x^5) / (1 - 22*x^2 + 36*x^4 - 16*x^6). - _Colin Barker_, Sep 26 2018
%e Some solutions for n=5:
%e ..x..0..x....x..0..x....x..0..x....x..0..x....x..0..x....x..0..x....x..0..x
%e ..1..x..2....1..x..0....1..x..2....1..x..1....0..x..1....0..x..1....1..x..2
%e ..x..1..x....x..2..x....x..1..x....x..2..x....x..1..x....x..2..x....x..0..x
%e ..0..x..0....0..x..0....0..x..1....1..x..1....2..x..0....2..x..0....1..x..2
%e ..x..1..x....x..2..x....x..0..x....x..2..x....x..2..x....x..1..x....x..0..x
%e ..2..x..0....1..x..0....2..x..2....0..x..0....0..x..0....2..x..0....2..x..2
%Y Column 2 of A231137.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 04 2013