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%I #9 Mar 29 2018 05:30:49
%S 3,9,32,129,513,2048,8193,32769,131072,524289,2097153,8388608,
%T 33554433,134217729,536870912,2147483649,8589934593,34359738368,
%U 137438953473,549755813889,2199023255552,8796093022209,35184372088833,140737488355328
%N Half the number of n X 2 0..2 arrays with no element equal its row sum plus its column sum mod 3.
%C Column 2 of A183429.
%H R. H. Hardin, <a href="/A183425/b183425.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n)=4*a(n-1) + a(n-3) - 4*a(n-4).
%F Empirical g.f.: x*(3 - 3*x - 4*x^2 - 2*x^3) / ((1 - x)*(1 - 4*x)*(1 + x + x^2)). - _Colin Barker_, Mar 29 2018
%e Some solutions for 4 X 2:
%e ..1..2....2..2....0..1....2..1....0..2....1..1....0..0....2..1....1..1....0..2
%e ..0..2....2..2....0..1....1..2....0..0....1..2....0..1....0..1....1..2....1..0
%e ..1..2....2..2....0..1....1..2....1..2....0..2....0..0....2..2....2..2....0..0
%e ..1..1....2..2....0..1....2..1....1..0....1..2....1..0....2..1....2..1....1..2
%Y Cf. A183429.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 04 2011
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