A203180 - OEIS

%I #5 Mar 31 2012 12:36:55

%S 5,18,235,2466,23083,223567,2208945,22411843,216858412,2141041521,

%T 21294389765,209517628754,2070288232686,20420464639642,

%U 201913230471755,1993188902599209,19665745111235770,194376407794905718

%N Number of nX7 0..2 arrays with every 1 immediately preceded by 0 to the left or above, no 0 immediately preceded by a 0, and every 2 immediately preceded by 0 1 to the left or above

%C Column 7 of A203181

%H R. H. Hardin, <a href="/A203180/b203180.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=5

%e ..0..1..2..0..1..0..1....0..1..0..1..2..0..1....0..1..0..1..2..0..1

%e ..1..0..1..2..0..1..0....1..0..1..2..0..1..0....1..0..1..0..1..2..0

%e ..0..1..0..1..1..2..1....0..1..0..1..1..0..1....0..1..0..1..2..0..1

%e ..1..0..1..0..1..0..1....1..0..1..0..2..1..2....1..2..1..2..0..1..0

%e ..0..1..2..1..0..1..0....2..1..0..1..2..0..1....0..1..0..1..1..0..1

%K nonn

%O 1,1

%A _R. H. Hardin_ Dec 30 2011