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A207854 Number of nX4 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 0 and 1 0 1 vertically.

%I A207854 #7 Jul 22 2025 20:53:21
%S A207854 9,81,289,1369,5929,26569,117649,522729,2319529,10297681,45711121,
%T A207854 202920025,900780169,3998665225,17750499361,78796419849,349785896329,
%U A207854 1552737795921,6892772417281,30597768825625,135826834143529
%N A207854 Number of nX4 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 0 and 1 0 1 vertically.
%C A207854 Column 4 of A207858
%H A207854 R. H. Hardin, <a href="/A207854/b207854.txt">Table of n, a(n) for n = 1..210</a>
%F A207854 Empirical: a(n) = 4*a(n-1) +a(n-2) +18*a(n-4) +4*a(n-5) -2*a(n-6) -8*a(n-7) -a(n-8) +a(n-10)
%e A207854 Some solutions for n=4
%e A207854 ..1..0..0..1....0..1..1..0....1..0..1..1....1..1..0..0....0..0..1..1
%e A207854 ..0..0..1..1....1..1..0..0....0..0..1..1....1..1..1..0....1..1..1..0
%e A207854 ..0..0..1..1....1..0..0..1....0..0..1..1....1..0..1..1....1..1..1..0
%e A207854 ..0..0..1..1....0..0..1..1....1..0..1..1....0..0..1..1....1..1..0..1
%K A207854 nonn
%O A207854 1,1
%A A207854 _R. H. Hardin_ Feb 21 2012