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 A185459 Number of (n+1) X 2 binary arrays with no 2 X 2 subblock determinant equal to any horizontal or vertical neighbor 2 X 2 subblock determinant. 1

%I #8 Apr 15 2018 08:59:26

%S 16,34,92,218,540,1320,3238,7934,19450,47672,116850,286412,702028,

%T 1720746,4217738,10338138,25339908,62110890,152240596,373158376,

%U 914652054,2241912374,5495172802,13469270464,33014657298,80922541380

%N Number of (n+1) X 2 binary arrays with no 2 X 2 subblock determinant equal to any horizontal or vertical neighbor 2 X 2 subblock determinant.

%C Column 1 of A185467.

%H R. H. Hardin, <a href="/A185459/b185459.txt">Table of n, a(n) for n = 1..200</a>

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

%F Empirical g.f.: 2*x*(8 + 9*x + 13*x^2 + 5*x^3 + 2*x^4) / (1 - x - 2*x^2 - 3*x^3 - 2*x^4). - _Colin Barker_, Apr 15 2018

%e Some solutions for 3 X 2:

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

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

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

%Y Cf. A185467.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 28 2011

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Last modified September 26 15:54 EDT 2023. Contains 365660 sequences. (Running on oeis4.)