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%I #7 Sep 26 2018 06:20:40
%S 1,3,4,11,15,42,57,161,218,617,835,2364,3199,9057,12256,34699,46955,
%T 132938,179893,509309,689202,1951253,2640455,7475596,10116051,
%U 28640333,38756384,109726191,148482575,420380482,568863057,1610552121,2179415178
%N Number of black square subarrays of (n+1) X (2+1) binary arrays with no element equal to a strict majority of its diagonal and antidiagonal neighbors, with upper left element zero.
%H R. H. Hardin, <a href="/A231067/b231067.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 5*a(n-2) - 5*a(n-4) + 2*a(n-6).
%F Empirical g.f.: x*(1 + 3*x - x^2 - 4*x^3 + 2*x^5) / (1 - 5*x^2 + 5*x^4 - 2*x^6). - _Colin Barker_, Sep 26 2018
%e Some solutions for n=4:
%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..1....0..x..1....1..x..1....1..x..0....1..x..0....1..x..1....1..x..1
%e ..x..1..x....x..1..x....x..0..x....x..1..x....x..1..x....x..0..x....x..0..x
%e ..0..x..0....0..x..1....1..x..0....1..x..0....0..x..1....0..x..0....0..x..1
%e ..x..1..x....x..0..x....x..1..x....x..0..x....x..0..x....x..1..x....x..1..x
%Y Column 2 of A231070.
%K nonn
%O 1,2
%A _R. H. Hardin_, Nov 03 2013
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