A207854 - OEIS

%I #5 Mar 31 2012 12:37:20

%S 9,81,289,1369,5929,26569,117649,522729,2319529,10297681,45711121,

%T 202920025,900780169,3998665225,17750499361,78796419849,349785896329,

%U 1552737795921,6892772417281,30597768825625,135826834143529

%N Number of nX4 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 0 and 1 0 1 vertically

%C Column 4 of A207858

%H R. H. Hardin, <a href="/A207854/b207854.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) +a(n-2) +18*a(n-4) +4*a(n-5) -2*a(n-6) -8*a(n-7) -a(n-8) +a(n-10)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 21 2012