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%I #9 Mar 05 2018 05:23:15
%S 6,36,90,261,624,1482,3808,9512,23280,58080,144996,359100,891940,
%T 2220008,5514460,13697376,34051032,84622140,210256020,522523332,
%U 1298558624,3226860476,8018895456,19927723520,49521161364,123062138780,305817249300
%N Number of 3 X n 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 0 1 vertically.
%C Row 3 of A207169.
%H R. H. Hardin, <a href="/A207171/b207171.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = a(n-1) + 9*a(n-3) + 2*a(n-4) + 2*a(n-5) - 12*a(n-6) - 8*a(n-7) + 8*a(n-9) for n>11.
%F Empirical g.f.: x*(6 + 30*x + 54*x^2 + 117*x^3 + 27*x^4 - 36*x^5 - 203*x^6 - 134*x^7 + 28*x^8 + 120*x^9 + 16*x^10) / (1 - x - 9*x^3 - 2*x^4 - 2*x^5 + 12*x^6 + 8*x^7 - 8*x^9). - _Colin Barker_, Mar 05 2018
%e Some solutions for n=4:
%e ..0..0..1..0....0..0..1..0....1..0..0..1....1..0..0..1....0..1..1..1
%e ..0..1..1..1....1..1..1..1....0..1..0..0....0..0..1..1....1..1..1..1
%e ..0..0..1..1....1..0..0..1....0..1..0..0....0..0..1..1....1..0..0..1
%Y Cf. A207169.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 15 2012
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