%I #8 Feb 07 2019 08:42:07
%S 0,2,3,10,27,76,214,599,1683,4721,13250,37183,104346,292828,821761,
%T 2306111,6471639,18161366,50966255,143026636,401375754,1126381063,
%U 3160963987,8870615501,24893614638,69858968603,196045273658,550161991984
%N Number of n X 2 0..1 arrays with every element both equal and not equal to some elements at offset (-1,0) (-1,1) (0,-1) (0,1) or (1,0), with upper left element zero.
%H R. H. Hardin, <a href="/A278088/b278088.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = a(n-1) + 4*a(n-2) + 3*a(n-3) for n>5.
%F Empirical g.f.: x^2*(2 + x - x^2 - x^3) / (1 - x - 4*x^2 - 3*x^3). - _Colin Barker_, Feb 07 2019
%e All solutions for n=4:
%e ..0..1. .0..0. .0..0. .0..1. .0..1. .0..1. .0..0. .0..1. .0..0. .0..0
%e ..0..1. .1..1. .1..1. .0..1. .0..1. .0..1. .1..1. .0..1. .1..1. .1..1
%e ..1..1. .0..1. .1..0. .0..1. .0..1. .0..0. .1..1. .1..0. .0..0. .0..1
%e ..0..0. .0..0. .1..0. .0..1. .0..0. .1..1. .0..0. .1..0. .1..1. .0..1
%Y Column 2 of A278094.
%K nonn
%O 1,2
%A _R. H. Hardin_, Nov 11 2016