%I #8 Sep 25 2018 08:53:14

%S 1,1,4,5,15,20,57,77,218,295,835,1130,3199,4329,12256,16585,46955,

%T 63540,179893,243433,689202,932635,2640455,3573090,10116051,13689141,

%U 38756384,52445525,148482575,200928100,568863057,769791157,2179415178,2949206335

%N Number of white 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="/A230983/b230983.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 + x - x^2) / (1 - 5*x^2 + 5*x^4 - 2*x^6). - _Colin Barker_, Sep 25 2018

%e Some solutions for n=6:

%e ..0..x..0....0..x..0....0..x..0....0..x..0....0..x..0....0..x..0....0..x..0

%e ..x..1..x....x..1..x....x..1..x....x..1..x....x..1..x....x..1..x....x..1..x

%e ..0..x..0....0..x..0....0..x..0....1..x..0....0..x..1....1..x..1....0..x..1

%e ..x..0..x....x..0..x....x..1..x....x..0..x....x..0..x....x..0..x....x..0..x

%e ..1..x..1....1..x..1....1..x..1....1..x..0....1..x..0....1..x..0....1..x..1

%e ..x..1..x....x..0..x....x..0..x....x..1..x....x..1..x....x..1..x....x..0..x

%e ..0..x..0....1..x..1....1..x..1....0..x..0....0..x..0....0..x..0....1..x..1

%Y Column 2 of A230989.

%K nonn

%O 1,3

%A _R. H. Hardin_, Nov 02 2013