A230246 - OEIS

%I #4 Oct 13 2013 16:25:07

%S 0,6,34,514,5838,64838,722386,8040426,89496950,996201406,11088801786,

%T 123430533890,1373917986238,15293224744246,170230491719618,

%U 1894853512698394,21091813842617094,234775199414692462

%N Number of nX3 0..3 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero

%C Column 3 of A230250

%H R. H. Hardin, <a href="/A230246/b230246.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 19*a(n-1) -112*a(n-2) +308*a(n-3) -443*a(n-4) +531*a(n-5) -1290*a(n-6) +2646*a(n-7) -1150*a(n-8) -3528*a(n-9) +4044*a(n-10) -384*a(n-11) +752*a(n-12) -384*a(n-13)

%e Some solutions for n=3

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_, Oct 13 2013