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%I #10 Oct 25 2018 08:13:12
%S 1,4,7,28,54,212,428,1652,3410,13004,27158,102740,215998,812892,
%T 1715842,6435860,13618366,50970780,108022954,403751540,856522206,
%U 3198552316,6789722794,25340854612,53813984430,200773770908,426474521338
%N Number of n X 3 0..2 arrays with no element equal to the sum of elements to its left or one plus the sum of elements above it, modulo 3.
%H R. H. Hardin, <a href="/A239025/b239025.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 17*a(n-2) - 96*a(n-4) + 210*a(n-6) - 152*a(n-8).
%F Empirical g.f.: x*(1 + 4*x - 10*x^2 - 40*x^3 + 31*x^4 + 120*x^5 - 28*x^6 - 104*x^7) / (1 - 17*x^2 + 96*x^4 - 210*x^6 + 152*x^8). - _Colin Barker_, Oct 25 2018
%e Some solutions for n=5:
%e ..2..0..0....2..0..0....2..0..0....2..0..0....2..0..0....2..0..0....2..0..0
%e ..1..0..0....1..0..2....1..0..0....1..2..2....1..0..0....2..0..0....2..0..0
%e ..2..0..0....2..0..1....2..0..0....2..1..1....2..0..0....1..0..2....1..0..0
%e ..1..2..2....1..2..2....1..2..2....2..0..0....2..0..0....2..0..1....2..0..0
%e ..2..1..1....2..1..2....2..1..2....1..0..2....1..2..2....1..0..0....1..0..2
%Y Column 3 of A239030.
%K nonn
%O 1,2
%A _R. H. Hardin_, Mar 09 2014
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