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%I #5 Mar 31 2012 12:36:15
%S 4,8,44,152,552,2000,7628,28440,108792,411888,1586424,6066032,
%T 23474384,90378912,351072012,1358520600,5293045208,20561697200,
%U 80309986856,312934745552,1224770426672,4784290151264,18757260263352,73421632108656
%N Number of arrangements of n+1 nonzero numbers x(i) in -2..2 with the sum of trunc(x(i)/x(i+1)) equal to zero
%C Column 2 of A189545
%H R. H. Hardin, <a href="/A189538/b189538.txt">Table of n, a(n) for n = 1..200</a>
%e Some solutions for n=5
%e .-2....2....1...-2...-1....2...-1....2...-1...-1...-2...-2...-1...-1....2....2
%e ..1...-2...-1...-1...-1...-1...-2...-1....1....2....2....2....1....2....2...-1
%e ..2....2...-2....1....1...-1...-2....2...-2...-1...-1...-2....1...-1...-2....1
%e .-2....2....2...-1...-1...-1...-2....1...-1...-2...-1...-2...-1...-1...-2....1
%e .-2...-2....1....1...-2....1....1....1....1...-2...-1...-1...-1...-1...-2...-2
%e .-1...-1...-2....1...-2....1...-2...-1...-2...-2...-1....1...-2...-2....1...-1
%K nonn
%O 1,1
%A _R. H. Hardin_ Apr 23 2011
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