%I #5 Mar 31 2012 12:37:17
%S 6,36,98,271,834,2307,6115,16544,44250,116526,307117,808976,2122787,
%T 5564987,14588870,38216326,100064540,261992129,685862456,1795255303,
%U 4698927663,12298716264,32188880680,84245176534,220486127041
%N Number of 3Xn 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 1 1 0 vertically
%C Row 3 of A207391
%H R. H. Hardin, <a href="/A207392/b207392.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) -2*a(n-2) +9*a(n-3) -15*a(n-4) -21*a(n-6) +16*a(n-7) +11*a(n-8) +27*a(n-9) +2*a(n-10) -12*a(n-12) -a(n-13) -2*a(n-14) +2*a(n-15)
%e Some solutions for n=4
%e ..1..0..0..0....1..1..1..1....1..1..1..1....0..0..0..0....0..0..0..0
%e ..1..0..1..1....0..0..0..0....1..1..1..1....0..1..1..1....0..1..1..0
%e ..1..0..1..1....0..1..1..1....1..1..1..1....0..1..1..0....0..1..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Feb 17 2012