%I #5 Mar 31 2012 12:36:09
%S 3139,17701,101419,596653,3703651,23126677,145502251,935121589,
%T 6025592131,38949920557,254629101139,1667294249173,10939228709659,
%U 72317298989221,478748984330419,3174887984002333,21179786460551971
%N Number of (n+2)X3 0..2 arrays with each 3X3 subblock having sum 9
%C Column 1 of A187645
%H R. H. Hardin, <a href="/A187640/b187640.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n)=7*a(n-1)+448*a(n-3)-3136*a(n-4)-60597*a(n-6)+424179*a(n-7)+3015306*a(n-9)-21107142*a(n-10)-49152096*a(n-12)+344064672*a(n-13)+216040608*a(n-15)-1512284256*a(n-16)
%e Some solutions for 4X3
%e ..2..0..0....0..0..1....1..2..0....2..0..2....1..2..0....2..0..2....1..2..0
%e ..0..2..2....2..1..1....1..1..0....0..1..0....1..2..0....2..0..0....2..2..0
%e ..1..1..1....2..2..0....2..1..1....1..2..1....2..1..0....2..1..0....0..1..1
%e ..0..1..1....0..0..1....0..1..2....2..0..2....1..1..1....2..2..0....1..1..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 12 2011