A231444 - OEIS

%I #8 Sep 28 2018 15:19:35

%S 2,6,23,102,492,2485,12858,67354,355003,1876862,9937840,52659593,

%T 279141170,1479959118,7847200511,41610135894,220644482580,

%U 1170015798397,6204298839786,32899919832226,174460671091171,925125214479854

%N Number of (n+1) X (1+1) 0..3 arrays with no element unequal to a strict majority of its horizontal and antidiagonal neighbors, with values 0..3 introduced in row major order.

%H R. H. Hardin, <a href="/A231444/b231444.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 11*a(n-1) - 41*a(n-2) + 65*a(n-3) - 43*a(n-4) + 9*a(n-5).

%F Empirical g.f.: x*(2 - 16*x + 39*x^2 - 35*x^3 + 9*x^4) / ((1 - x)*(1 - 3*x + x^2)*(1 - 7*x + 9*x^2)). - _Colin Barker_, Sep 28 2018

%e Some solutions for n=7:

%e ..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0

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

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

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

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

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

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

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

%Y Column 1 of A231451.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 09 2013