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A222505 Number of nX4 0..1 arrays with exactly floor(nX4/2) elements unequal to at least one horizontal, diagonal or antidiagonal neighbor, with new values introduced in row major 0..1 order.

%I A222505 #6 Jul 23 2025 02:41:13
%S A222505 3,3,15,84,497,2862,15420,86570,484976,2751326,15597305,89022483,
%T A222505 508390703,2915183250,16739260404,96360825455,555513635334,
%U A222505 3208071753051,18550893260858,107413402302763,622649366897782,3613180083184007
%N A222505 Number of nX4 0..1 arrays with exactly floor(nX4/2) elements unequal to at least one horizontal, diagonal or antidiagonal neighbor, with new values introduced in row major 0..1 order.
%C A222505 Column 4 of A222509
%H A222505 R. H. Hardin, <a href="/A222505/b222505.txt">Table of n, a(n) for n = 1..177</a>
%e A222505 Some solutions for n=3
%e A222505 ..0..0..1..1....0..0..1..1....0..0..0..0....0..0..0..0....0..0..0..0
%e A222505 ..1..1..1..1....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
%e A222505 ..1..1..1..1....0..0..0..0....1..1..0..0....0..1..0..1....0..0..1..1
%K A222505 nonn
%O A222505 1,1
%A A222505 _R. H. Hardin_ Feb 23 2013