%I #4 Mar 05 2013 03:06:29
%S 0,20,96,465,2608,15077,89811,544302,3349328,20823047,130535918,
%T 823585242,5221057054,33231082276,212180118775,1358528423728,
%U 8718262087314,56062919553225,361148981248207,2330144611056838
%N Number of 4Xn 0..1 arrays with exactly floor(4Xn/2) elements unequal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..1 order
%C Row 4 of A222769
%H R. H. Hardin, <a href="/A222772/b222772.txt">Table of n, a(n) for n = 1..45</a>
%e Some solutions for n=3
%e ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..1....0..0..1....0..0..0
%e ..0..1..0....1..1..1....0..0..1....0..0..0....0..1..0....0..0..0....0..0..1
%e ..1..0..0....0..1..1....0..0..0....0..1..0....0..0..0....0..1..1....0..0..1
%e ..0..0..0....1..1..1....0..1..1....0..1..1....0..0..0....1..1..1....0..1..1
%K nonn
%O 1,2
%A _R. H. Hardin_ Mar 05 2013