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Number of nX4 0..2 arrays with no element equal to one or three horizontal or vertical neighbors, with new values 0..2 introduced in row major order
1

%I #4 Apr 16 2014 06:48:44

%S 4,36,294,2436,19814,162776,1333934,10937316,89651534,734979136,

%T 6025149574,49393306556,404916355574,3319433387656,27212098788254,

%U 223079838087956,1828767624421854,14991902921730896,122900877847563254

%N Number of nX4 0..2 arrays with no element equal to one or three horizontal or vertical neighbors, with new values 0..2 introduced in row major order

%C Column 4 of A241108

%H R. H. Hardin, <a href="/A241104/b241104.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) +21*a(n-2) -12*a(n-3) +8*a(n-4) -688*a(n-5) -1648*a(n-6) -768*a(n-7) -2304*a(n-8) +8192*a(n-9) +16384*a(n-10)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 16 2014