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%I #4 Mar 31 2012 12:36:11
%S 0,4132,51196,368588,1399640,4875112,11953848,28779900,58731504,
%T 116157280,200181920,362242468,569517636
%N Number of arrangements of 8 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero
%C Row 6 of A188249
%e Some solutions for n=4
%e .-4...-1....1...-4....3...-2...-2...-2...-4....1....1...-3....4...-4...-2....2
%e .-2...-4...-3...-3...-4...-4...-2...-3...-2...-3...-4...-2...-4...-4...-4...-3
%e ..4...-2...-3....2...-4...-1....3....1....3...-2....3...-2....1....4...-4....3
%e ..3....2....1...-1....3...-3...-2...-3....2....2....4....1....3...-2...-4...-3
%e .-3...-1....3...-2....3....3...-4...-3...-1...-2...-1...-2....3...-2....3...-3
%e ..1....1...-2....4...-1...-2....3....2...-2...-1....2....4....3...-2...-4...-1
%e .-3...-1...-4....1....2...-2....2....3...-4....3....2....1....1....3....2...-3
%e .-1....4....2...-2....2....2....3...-3....4....2....3...-2...-4....2...-4...-3
%K nonn
%O 1,2
%A _R. H. Hardin_ Mar 25 2011
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