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A185479 Number of (n+1) X 2 binary arrays with every 2 X 2 subblock determinant equal to some horizontal or vertical neighbor 2 X 2 subblock determinant. 2

%I

%S 0,30,76,234,632,1832,5182,14860,42346,121016,345376,986330,2815960,

%T 8040658,22957720,65550976,187164486,534405148,1525866290,4356753200,

%U 12439678168,35518569746,101414891304,289566302122,826788250864

%N Number of (n+1) X 2 binary arrays with every 2 X 2 subblock determinant equal to some horizontal or vertical neighbor 2 X 2 subblock determinant.

%C Column 1 of A185487.

%H R. H. Hardin, <a href="/A185479/b185479.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 3*a(n-1) + a(n-2) - 5*a(n-3) + 3*a(n-4) - 2*a(n-6) for n>7.

%F Empirical g.f.: 2*x^2*(15 - 7*x - 12*x^2 + 2*x^3 - 4*x^4 - 2*x^5) / (1 - 3*x - x^2 + 5*x^3 - 3*x^4 + 2*x^6). - _Colin Barker_, Feb 27 2018

%e Some solutions for 3 X 2:

%e ..1..1....1..0....1..0....1..1....0..1....0..0....0..1....1..1....1..1....1..0

%e ..0..0....0..0....1..0....1..1....0..0....0..0....0..0....1..1....0..0....0..0

%e ..1..1....1..0....0..0....0..0....0..1....0..0....1..1....1..1....1..0....1..1

%Y Cf. A185487.

%K nonn

%O 1,2

%A _R. H. Hardin_, Jan 28 2011

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Last modified January 20 11:11 EST 2020. Contains 331083 sequences. (Running on oeis4.)