A209508 - OEIS

%I #5 Mar 31 2012 12:37:29

%S 729,11673,189801,3102219,50798448,832374135,13642432110,223616134827,

%T 3665458427859,60083950172598,984896234494740,16144445659742595,

%U 264640335145278948,4337994781387301094,71108586231270845148

%N Half the number of (n+1)X6 0..2 arrays with every 2X2 subblock having two or four distinct clockwise edge differences

%C Column 5 of A209511

%H R. H. Hardin, <a href="/A209508/b209508.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 30*a(n-1) -291*a(n-2) +1278*a(n-3) -2901*a(n-4) +3519*a(n-5) -2152*a(n-6) +516*a(n-7)

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 09 2012