A210348 - OEIS

%I #10 Jul 15 2018 12:02:51

%S 40,431,4615,49484,530580,5689274,61005068,654148428,7014344012,

%T 75213872216,806508362752,8648082333016,92732242176864,

%U 994355562040080,10662343125623728,114330894613824704,1225955056113872768

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

%C Column 1 of A210355.

%H R. H. Hardin, <a href="/A210348/b210348.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 14*a(n-1) - 30*a(n-2) - 66*a(n-3) + 104*a(n-4) + 136*a(n-5).

%F Empirical g.f.: x*(5 - 18*x)*(8 + 3*x - 33*x^2 - 30*x^3) / (1 - 14*x + 30*x^2 + 66*x^3 - 104*x^4 - 136*x^5). - _Colin Barker_, Jul 15 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Cf. A210355.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 20 2012