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A221690 Number of nX4 arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, without consecutive moves in the same direction.

%I A221690 #6 Jul 23 2025 02:07:03
%S A221690 13,1336,95076,7033429,520770016,38558774282,2854945130275,
%T A221690 211383822013331,15651127479431664,1158829375610866111,
%U A221690 85801199678309146886,6352829859620504245102,470371595862197876296617
%N A221690 Number of nX4 arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, without consecutive moves in the same direction.
%C A221690 Column 4 of A221693
%H A221690 R. H. Hardin, <a href="/A221690/b221690.txt">Table of n, a(n) for n = 1..78</a>
%e A221690 Some solutions for n=3
%e A221690 ..0..3..1..0....1..0..2..1....2..1..0..1....0..1..2..0....2..0..1..1
%e A221690 ..0..0..4..2....1..0..0..3....0..2..2..2....3..1..1..2....0..2..0..3
%e A221690 ..1..0..1..0....1..2..1..0....0..0..0..2....0..0..2..0....2..0..0..1
%K A221690 nonn
%O A221690 1,1
%A A221690 _R. H. Hardin_ Jan 22 2013