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A207694 Number of 3 X n 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 1 1 vertically.

%I A207694 #8 Mar 05 2018 11:15:09
%S A207694 6,36,60,100,240,576,1296,2916,6804,15876,36288,82944,191808,443556,
%T A207694 1018980,2340900,5397840,12446784,28640304,65901924,151822836,
%U A207694 349764804,805233312,1853819136,4269519072,9833102244,22641659460,52134588900
%N A207694 Number of 3 X n 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 1 1 vertically.
%C A207694 Row 3 of A207693.
%H A207694 R. H. Hardin, <a href="/A207694/b207694.txt">Table of n, a(n) for n = 1..210</a>
%F A207694 Empirical: a(n) = a(n-1) + 3*a(n-3) + 9*a(n-4) for n>7.
%F A207694 Empirical g.f.: 2*x*(3 + 15*x + 12*x^2 + 11*x^3 - 11*x^4 - 84*x^5 - 60*x^6) / ((1 + 3*x^2)*(1 - x - 3*x^2)). - _Colin Barker_, Mar 05 2018
%e A207694 Some solutions for n=4:
%e A207694 ..1..0..0..1....1..0..0..1....0..0..1..1....0..0..1..1....0..1..1..0
%e A207694 ..0..1..1..0....1..1..1..0....1..1..1..0....1..1..0..0....1..0..0..1
%e A207694 ..1..0..0..1....0..0..1..1....1..1..0..1....0..0..1..1....0..0..1..1
%Y A207694 Cf. A207693.
%K A207694 nonn
%O A207694 1,1
%A A207694 _R. H. Hardin_, Feb 19 2012