|
%I #5 Mar 31 2012 12:37:17
%S 9,81,361,1521,6889,29929,127449,546121,2337841,9979281,42601729,
%T 181899169,776458225,3314189761,14146485721,60382741441,257733905625,
%U 1100096811025,4695589958761,20042356043161,85547497157721
%N Number of nX4 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 0 1 0 vertically
%C Column 4 of A207426
%H R. H. Hardin, <a href="/A207422/b207422.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 4*a(n-1) +a(n-2) +8*a(n-3) -21*a(n-4) -46*a(n-5) -6*a(n-6) +35*a(n-7) +49*a(n-8) +19*a(n-9) -16*a(n-10) -21*a(n-11) -4*a(n-13) -2*a(n-14) +a(n-15)
%e Some solutions for n=4
%e ..1..0..0..1....1..0..1..1....1..0..1..1....0..1..1..1....1..0..0..1
%e ..0..1..1..0....0..0..1..1....0..1..1..1....1..0..0..1....1..0..1..1
%e ..1..1..1..1....1..0..1..1....0..1..1..1....1..0..0..1....0..0..1..1
%e ..1..1..1..1....1..0..0..1....0..0..1..1....1..0..0..1....1..0..0..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Feb 17 2012
| 