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A207924 Number of n X 4 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 0 and 1 1 1 vertically.

%I A207924 #8 Mar 06 2018 08:55:02
%S A207924 9,81,144,576,1936,6400,21904,73984,250000,846400,2862864,9684544,
%T A207924 32764176,110838784,374964496,1268499456,4291298064,14517358144,
%U A207924 49111878544,166144281664,562062085264,1901442429184,6432533627536
%N A207924 Number of n X 4 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 0 and 1 1 1 vertically.
%C A207924 Column 4 of A207928.
%C A207924 It seems that all terms are squares. - _Colin Barker_, Mar 06 2018
%H A207924 R. H. Hardin, <a href="/A207924/b207924.txt">Table of n, a(n) for n = 1..210</a>
%F A207924 Empirical: a(n) = 2*a(n-1) + 3*a(n-2) + 6*a(n-3) - a(n-4) - a(n-6) for n>8.
%F A207924 Empirical g.f.: x*(9 + 63*x - 45*x^2 - 9*x^3 - 125*x^4 + 17*x^5 - 7*x^6 + 17*x^7) / ((1 + x + x^2 - x^3)*(1 - 3*x - x^2 - x^3)). - _Colin Barker_, Mar 06 2018
%e A207924 Some solutions for n=8:
%e A207924 ..0..1..1..0....1..0..0..1....1..0..0..1....1..0..1..1....0..1..1..0
%e A207924 ..1..0..0..1....0..1..1..0....0..1..1..0....0..0..1..1....0..1..1..1
%e A207924 ..1..1..1..1....1..0..1..1....0..0..1..1....1..1..0..0....1..0..0..1
%e A207924 ..0..1..1..0....1..1..0..1....1..0..0..1....1..0..1..1....0..1..1..0
%e A207924 ..1..0..0..1....0..1..1..0....1..1..0..0....0..0..1..1....0..1..1..1
%e A207924 ..1..0..1..1....0..0..1..1....0..1..1..0....1..1..0..0....1..0..0..1
%e A207924 ..0..1..1..0....1..1..0..1....0..0..1..1....1..0..1..1....1..1..1..0
%e A207924 ..1..1..0..1....1..1..1..0....1..0..0..1....0..1..1..1....0..1..1..1
%Y A207924 Cf. A207928.
%K A207924 nonn
%O A207924 1,1
%A A207924 _R. H. Hardin_, Feb 21 2012