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Number of nX3 0..2 arrays with no element equal to fewer vertical neighbors than horizontal neighbors, with new values 0..2 introduced in row major order
1

%I #4 Apr 20 2014 12:00:20

%S 2,28,460,7376,118488,1904096,30598800,491723328,7902006144,

%T 126985443680,2040659387360,32793449527584,526991588462752,

%U 8468768559462432,136093331438385952,2187023382674637856,35145522751283965984

%N Number of nX3 0..2 arrays with no element equal to fewer vertical neighbors than horizontal neighbors, with new values 0..2 introduced in row major order

%C Column 3 of A241370

%H R. H. Hardin, <a href="/A241365/b241365.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 15*a(n-1) +18*a(n-2) -8*a(n-3) -68*a(n-4) -164*a(n-5) -256*a(n-6) -176*a(n-7) +64*a(n-8)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 20 2014