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A208554 Number of nX7 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 0 1 1 vertically.

%I A208554 #10 Jul 22 2025 21:24:25
%S A208554 42,1764,10710,65025,221340,753424,1913940,4862025,10332630,21958596,
%T A208554 41363322,77915929,134523480,232257600,375406920,606784689,931373730,
%U A208554 1429596100,2104920510,3099260241,4409811252,6274540944,8675694300
%N A208554 Number of nX7 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 0 1 1 vertically.
%C A208554 Column 7 of A208555
%H A208554 R. H. Hardin, <a href="/A208554/b208554.txt">Table of n, a(n) for n = 1..210</a>
%H A208554 Robert Israel, <a href="/A208554/a208554.pdf">Maple-assisted proof of formula</a>
%F A208554 Empirical: a(n) = 2*a(n-1) +6*a(n-2) -14*a(n-3) -14*a(n-4) +42*a(n-5) +14*a(n-6) -70*a(n-7) +70*a(n-9) -14*a(n-10) -42*a(n-11) +14*a(n-12) +14*a(n-13) -6*a(n-14) -2*a(n-15) +a(n-16).
%F A208554 Empirical formula verified (see link). - _Robert Israel_, Sep 27 2018
%e A208554 Some solutions for n=4
%e A208554 ..1..1..1..1..0..1..0....1..1..0..1..0..1..0....1..1..0..1..0..1..0
%e A208554 ..0..1..1..0..1..0..0....0..1..0..1..0..1..0....1..0..1..0..1..1..1
%e A208554 ..0..1..0..1..0..1..0....0..1..0..1..0..1..0....0..1..0..1..0..1..0
%e A208554 ..0..1..1..0..1..0..0....0..1..0..1..0..1..0....1..0..1..0..1..0..1
%K A208554 nonn
%O A208554 1,1
%A A208554 _R. H. Hardin_ Feb 28 2012