A267638 - OEIS

%I #6 Jan 29 2016 18:02:00

%S 2,8,18,50,98,242,450,1058,1922,4418,7938,18050,32258,72962,130050,

%T 293378,522242,1176578,2093058,4712450,8380418,18862082,33538050,

%U 75472898,134184962,301940738,536805378,1207861250,2147352578,4831641602

%N Number of nX2 0..1 arrays with every repeated value in every row and column unequal to the previous repeated value, and new values introduced in row-major sequential order.

%C Column 2 of A267644.

%H R. H. Hardin, <a href="/A267638/b267638.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +6*a(n-2) -6*a(n-3) -8*a(n-4) +8*a(n-5).

%F Empirical: G.f.: -2*x*(1+3*x-x^2-2*x^3+2*x^4) / ( (x-1)*(2*x+1)*(2*x-1)*(2*x^2-1) ). - _R. J. Mathar_, Jan 26 2016

%e Some solutions for n=6

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

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

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

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

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

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

%Y Cf. A267644.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 18 2016