A185461 - OEIS

%I #8 Apr 15 2018 09:16:39

%S 92,240,866,2766,8762,27102,83688,258056,795746,2453840,7566872,

%T 23333794,71953944,221882868,684215602,2109901528,6506259672,

%U 20063218306,61868531104,190782709036,588312691858,1814167673456,5594311312512

%N Number of (n+1) X 4 binary arrays with no 2 X 2 subblock determinant equal to any horizontal or vertical neighbor 2 X 2 subblock determinant.

%C Column 3 of A185467.

%H R. H. Hardin, <a href="/A185461/b185461.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 2*a(n-1) + 2*a(n-2) + 3*a(n-3) + 2*a(n-4) + 4*a(n-5) + 2*a(n-6) for n>12.

%F Empirical g.f.: 2*x*(46 + 28*x + 101*x^2 + 139*x^3 + 297*x^4 + 300*x^5 + 393*x^6 + 357*x^7 + 316*x^8 + 194*x^9 + 112*x^10 + 32*x^11) / (1 - 2*x - 2*x^2 - 3*x^3 - 2*x^4 - 4*x^5 - 2*x^6). - _Colin Barker_, Apr 15 2018

%e Some solutions for 3 X 4:

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

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

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

%Y Cf. A185467.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 28 2011