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A207438 Number of nX4 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 1 0 0 vertically.

%I A207438 #7 Jul 22 2025 20:26:01
%S A207438 9,81,323,1360,6525,32393,165626,855471,4449491,23211486,121314285,
%T A207438 634633939,3321850282,17392770603,91082814851,477033173168,
%U A207438 2498544485965,13087020633451,68549369291830,359063591740895,1880798904630019
%N A207438 Number of nX4 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 1 0 0 vertically.
%C A207438 Column 4 of A207442
%H A207438 R. H. Hardin, <a href="/A207438/b207438.txt">Table of n, a(n) for n = 1..210</a>
%F A207438 Empirical: a(n) = 8*a(n-1) +a(n-2) -120*a(n-3) +106*a(n-4) +730*a(n-5) -804*a(n-6) -2308*a(n-7) +2565*a(n-8) +4000*a(n-9) -4254*a(n-10) -3640*a(n-11) +3811*a(n-12) +1460*a(n-13) -1708*a(n-14) -82*a(n-15) +284*a(n-16) -48*a(n-17) for n>18
%e A207438 Some solutions for n=4
%e A207438 ..0..0..0..0....1..1..0..1....1..0..0..0....1..0..1..1....0..0..0..0
%e A207438 ..1..0..1..1....1..0..1..1....0..1..1..1....1..0..1..1....1..1..1..0
%e A207438 ..1..0..0..0....0..1..1..1....1..0..0..0....0..0..0..0....1..1..1..0
%e A207438 ..1..0..1..1....1..1..0..0....0..1..1..1....1..0..1..1....1..1..0..0
%K A207438 nonn
%O A207438 1,1
%A A207438 _R. H. Hardin_ Feb 17 2012