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A207120 Number of nX5 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 0 1 1 vertically.

%I A207120 #7 Jul 22 2025 20:02:56
%S A207120 14,196,896,4096,12288,36864,87744,208849,428666,879844,1628368,
%T A207120 3013696,5166336,8856576,14311584,23126481,35653926,54967396,81554000,
%U A207120 121000000,173888000,249892864,349562304,488984769,668387538,913611076,1224032096
%N A207120 Number of nX5 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 0 1 1 vertically.
%C A207120 Column 5 of A207123
%H A207120 R. H. Hardin, <a href="/A207120/b207120.txt">Table of n, a(n) for n = 1..210</a>
%F A207120 Empirical: a(n) = 2*a(n-1) +8*a(n-2) -18*a(n-3) -27*a(n-4) +72*a(n-5) +48*a(n-6) -168*a(n-7) -42*a(n-8) +252*a(n-9) -252*a(n-11) +42*a(n-12) +168*a(n-13) -48*a(n-14) -72*a(n-15) +27*a(n-16) +18*a(n-17) -8*a(n-18) -2*a(n-19) +a(n-20)
%e A207120 Some solutions for n=4
%e A207120 ..0..1..1..0..0....0..0..0..0..0....1..0..0..0..0....0..1..1..0..0
%e A207120 ..1..1..1..1..1....1..0..1..1..0....1..0..1..1..1....1..0..1..1..1
%e A207120 ..0..0..0..0..0....0..0..0..0..0....0..0..0..0..0....0..1..1..0..0
%e A207120 ..0..1..1..0..0....1..0..0..0..0....0..0..0..0..0....0..0..0..0..0
%K A207120 nonn
%O A207120 1,1
%A A207120 _R. H. Hardin_ Feb 15 2012