%I #6 Dec 18 2015 18:17:32
%S 0,7,702,751266,5033988714,268995986029278
%N 1/4 the number of n X n 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors
%C Diagonal of A186168
%e Some solutions for 4X4 with a(1,1)=0
%e ..0..2..0..2....0..0..2..0....0..2..1..1....0..0..2..2....0..2..2..1
%e ..0..2..0..2....0..0..2..0....0..2..0..0....0..2..1..2....0..0..0..1
%e ..1..2..3..3....2..3..3..3....2..1..1..0....2..2..1..0....2..3..3..1
%e ..1..1..1..1....2..3..2..2....2..2..1..0....3..3..3..0....2..3..0..0
%K nonn
%O 1,2
%A _R. H. Hardin_ Feb 13 2011
