A205911 - OEIS

%I #7 Dec 10 2015 02:15:26

%S 369,1791,9831,60108,387267,2554848,17051166,114537918,772431777,

%T 5222734311,35375284446,239899338933,1628261283648,11057930844258,

%U 75127872458898,510566050100991,3470474714680779,23593143064954278

%N Number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock having the same number of clockwise edge increases as its horizontal neighbors and the same number of counterclockwise edge increases as its vertical neighbors.

%C Column 2 of A205917.

%H R. H. Hardin, <a href="/A205911/b205911.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 16*a(n-1) -83*a(n-2) +110*a(n-3) +335*a(n-4) -960*a(n-5) -146*a(n-6) +2173*a(n-7) -531*a(n-8) -2598*a(n-9) +775*a(n-10) +2149*a(n-11) -993*a(n-12) -552*a(n-13) +306*a(n-14) for n>15.

%e Some solutions for n=4:

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 01 2012