A228656 - OEIS

%I #9 Sep 02 2013 02:50:28

%S 3,14,78,416,2228,11912,63688,340480,1820208,9730784,52020448,

%T 278099456,1486709568,7947894912,42489154688,227145461760,

%U 1214311301888,6491663650304,34704195603968,185527355908096,991822435038208

%N Number of nX4 binary arrays with top left value 1 and no two ones adjacent horizontally, diagonally or antidiagonally.

%C Column 4 of A228660

%H R. H. Hardin, <a href="/A228656/b228656.txt">Table of n, a(n) for n = 1..210</a>

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

%F Empirical: G.f. -x*(-3+4*x) / ( 1-6*x+2*x^2+8*x^3 ). - _R. J. Mathar_, Aug 29 2013

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Aug 29 2013