A210329 - OEIS

%I #5 Mar 31 2012 12:37:33

%S 406,11877,344659,10050240,293095459,8549740834,249408131339,

%T 7275728429567,212248230477148,6191735605717011,180626272896775892,

%U 5269258543534397671,153715660936507360882,4484218150761298939517

%N 1/4 the number of (n+1)X3 0..3 arrays with every 2X2 subblock having two or three distinct clockwise edge differences

%C Column 2 of A210335

%H R. H. Hardin, <a href="/A210329/b210329.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 47*a(n-1) -547*a(n-2) -255*a(n-3) +35216*a(n-4) -129394*a(n-5) -465060*a(n-6) +2920628*a(n-7) +320982*a(n-8) -20531472*a(n-9) +17232541*a(n-10) +55329403*a(n-11) -75077657*a(n-12) -49764339*a(n-13) +111287472*a(n-14) -12747232*a(n-15) -52250238*a(n-16) +26800488*a(n-17) -2501204*a(n-18) -451078*a(n-19) -5036*a(n-20)

%e Some solutions for n=4

%e ..3..0..1....1..2..1....1..3..3....2..1..1....2..1..3....1..3..1....1..0..0

%e ..2..1..2....1..3..2....3..1..1....0..0..0....2..1..1....1..1..1....0..0..1

%e ..3..1..1....1..3..1....1..3..2....1..0..1....2..0..1....2..3..2....1..2..1

%e ..1..3..3....1..3..2....3..1..1....1..0..1....2..1..0....1..1..1....1..0..0

%e ..3..1..3....1..1..2....1..1..2....0..0..1....0..0..1....3..3..1....0..0..3

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 20 2012