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A186165 1/4 the number of nX6 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

%I A186165 #6 Jul 22 2025 10:17:19
%S A186165 19,14748,4762206,1899336597,704281652979,268995986029278,
%T A186165 101554003879403823,38514280297010210802
%N A186165 1/4 the number of nX6 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.
%C A186165 Column 6 of A186168
%e A186165 Some solutions for 4X6 with a(1,1)=0
%e A186165 ..0..0..0..2..2..2....0..0..0..2..2..0....0..0..0..2..2..0....0..0..0..2..2..0
%e A186165 ..0..2..0..0..0..2....0..2..0..0..2..0....0..2..0..0..0..0....0..2..0..0..3..0
%e A186165 ..3..2..1..2..0..3....3..2..1..1..2..0....0..2..2..2..2..2....1..2..2..3..3..0
%e A186165 ..3..1..1..2..0..3....3..0..0..0..2..0....0..0..0..0..1..1....1..0..0..3..2..2
%K A186165 nonn
%O A186165 1,1
%A A186165 _R. H. Hardin_ Feb 13 2011