%I #9 Sep 26 2018 15:44:18
%S 18,100,570,3234,18376,104386,593022,3368932,19138850,108727402,
%T 617678248,3509017866,19934661174,113248415924,643362012010,
%U 3654926870610,20763567293192,117957415290738,670113744215758
%N Number of (n+1) X (1+1) 0..2 arrays with no element equal to a strict majority of its horizontal and vertical neighbors, with upper left element zero.
%H R. H. Hardin, <a href="/A231138/b231138.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 6*a(n-1) - 11*a(n-3) + 4*a(n-4).
%F Empirical g.f.: 2*x*(9 - 4*x - 15*x^2 + 6*x^3) / (1 - 6*x + 11*x^3 - 4*x^4). - _Colin Barker_, Sep 26 2018
%e Some solutions for n=3:
%e ..0..2....0..1....0..1....0..1....0..1....0..2....0..1....0..2....0..1....0..2
%e ..1..2....2..0....1..2....1..0....0..1....1..2....2..2....0..1....0..2....1..1
%e ..0..1....1..2....1..0....1..0....2..0....0..1....1..0....2..2....2..0....2..0
%e ..2..1....0..2....2..2....0..1....0..2....0..2....0..2....0..1....2..0....2..0
%Y Column 1 of A231144.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 04 2013