A210384 - OEIS

%I #8 Jul 15 2018 12:03:13

%S 597,13399,300653,6747079,151416037,3398046223,76258263901,

%T 1711372650743,38406282159749,861906092362239,19342723916497469,

%U 434085536538192695,9741660680711022261,218620398125347551423,4906235193671989155869

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

%C Column 2 of A210390.

%H R. H. Hardin, <a href="/A210384/b210384.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 26*a(n-1) - 76*a(n-2) - 93*a(n-3) + 144*a(n-4) + 66*a(n-5) - 32*a(n-6).

%F Empirical g.f.: x*(597 - 2123*x - 2349*x^2 + 3946*x^3 + 1750*x^4 - 864*x^5) / (1 - 26*x + 76*x^2 + 93*x^3 - 144*x^4 - 66*x^5 + 32*x^6). - _Colin Barker_, Jul 15 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Cf. A210390.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 20 2012