A232145 - OEIS

%I #9 Mar 19 2018 09:30:37

%S 3,23,145,887,5487,33957,210039,1299219,8036625,49712291,307505983,

%T 1902144221,11766121259,72781867263,450207854133,2784857267659,

%U 17226332081291,106557172756085,659132252427443,4077203954957651

%N Number of n X 2 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally, diagonally or antidiagonally.

%C Column 2 of A232149.

%H R. H. Hardin, <a href="/A232145/b232145.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) + 6*a(n-2) + 8*a(n-3) + 3*a(n-4) - 8*a(n-5) - 5*a(n-6).

%F Empirical g.f.: x*(3 + 8*x + 12*x^2 - 11*x^4 - 5*x^5) / (1 - 5*x - 6*x^2 - 8*x^3 - 3*x^4 + 8*x^5 + 5*x^6). - _Colin Barker_, Mar 19 2018

%e Some solutions for n=6:

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

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

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

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

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

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

%Y Cf. A232149.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 19 2013