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A208121 Number of 6 X n 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 0 1 1 vertically.

%I A208121 #8 Jun 28 2018 10:54:51
%S A208121 16,256,784,2401,17689,130321,577600,2560000,15054400,88529281,
%T A208121 443060401,2217373921,12151975696,66597028096,346652467984,
%U A208121 1804403844961,9669593502409,51818243883121,273150984198400,1439868559360000
%N A208121 Number of 6 X n 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 0 1 1 vertically.
%C A208121 Row 6 of A208118.
%H A208121 R. H. Hardin, <a href="/A208121/b208121.txt">Table of n, a(n) for n = 1..210</a>
%F A208121 Empirical: a(n) = 7*a(n-1) - 21*a(n-2) + 84*a(n-3) - 756*a(n-5) + 1701*a(n-6) - 5103*a(n-7) + 6561*a(n-8).
%F A208121 Empirical g.f.: x*(16 + 144*x - 672*x^2 + 945*x^3 - 4158*x^4 + 3159*x^5 + 1458*x^6 + 6561*x^7) / ((1 - 3*x)*(1 + 3*x)*(1 - 7*x + 9*x^2)*(1 + 21*x^2 + 81*x^4)). - _Colin Barker_, Jun 28 2018
%e A208121 Some solutions for n=4:
%e A208121 ..1..0..0..1....0..1..1..1....1..1..0..1....1..1..1..0....0..0..1..1
%e A208121 ..1..1..1..0....0..0..1..1....1..0..1..1....1..0..1..1....0..1..1..1
%e A208121 ..1..0..0..1....0..0..1..1....1..1..0..0....0..1..1..0....0..0..1..1
%e A208121 ..0..1..1..0....0..0..1..1....0..0..1..1....0..0..1..1....0..1..1..1
%e A208121 ..1..0..0..1....0..0..1..1....1..1..0..0....0..1..1..0....0..0..1..1
%e A208121 ..0..1..1..0....0..0..1..1....0..0..1..1....0..0..1..1....0..1..1..1
%Y A208121 Cf. A208118.
%K A208121 nonn
%O A208121 1,1
%A A208121 _R. H. Hardin_, Feb 23 2012