A230063 - OEIS

%I #6 Mar 21 2016 07:35:57

%S 0,9,45,441,3645,31329,266805,2277081,19424205,165714129,1413721125,

%T 12060652041,102890947005,877775988609,7488419962005,63884675998521,

%U 545008403548845,4649536929125169,39665798745571845,338394040998364521

%N Number of nX3 0..2 arrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value 2-x(i,j)

%C Column 3 of A230068

%H R. H. Hardin, <a href="/A230063/b230063.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 7*a(n-1) +14*a(n-2) -8*a(n-3).

%F Empirical: G.f.: -9*x^2*(-1+2*x) / ( (2*x+1)*(4*x^2-9*x+1) ). - _R. J. Mathar_, Mar 21 2016

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_, Oct 08 2013