A231971 - OEIS

%I #8 Oct 01 2018 21:09:50

%S 16,56,169,550,1764,5680,18225,58596,188356,605458,1946025,6255180,

%T 20106256,64627982,207734569,667725402,2146283584,6898841796,

%U 22175081569,71277802674,229109651716,736431677100,2367126871209,7608702637640

%N Number of (n+1) X (2+1) 0..1 arrays with no element having a strict majority of its horizontal and vertical neighbors equal to one.

%H R. H. Hardin, <a href="/A231971/b231971.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) + 2*a(n-3) + 4*a(n-4) - 10*a(n-5) - 2*a(n-6) - a(n-8) + a(n-9).

%F Empirical g.f.: x*(16 + 8*x + x^2 + 11*x^3 - 62*x^4 - 14*x^5 + x^6 - 5*x^7 + 6*x^8) / ((1 - 3*x - x^2 + x^3)*(1 + x^2 - 3*x^4 - x^6)). - _Colin Barker_, Oct 01 2018

%e Some solutions for n=2:

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

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

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

%Y Column 2 of A231977.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 16 2013