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%I #5 Mar 31 2012 12:36:11
%S 100,208,3292,16484,193232,1399640,14715004,123729664,1247614580,
%T 11199296500,110995324320,1029900778912,10129893228408,95800929304216,
%U 939159329686860,8989025842005012,88016972322771816,849227228527469216
%N Number of arrangements of n+2 nonzero numbers x(i) in -5..5 with the sum of x(i)*x(i+1) equal to zero
%C Column 5 of A188249
%H R. H. Hardin, <a href="/A188245/b188245.txt">Table of n, a(n) for n = 1..42</a>
%e Some solutions for n=4
%e .-5....1....2...-4....4...-2....2....5....1...-2...-3...-1...-3....4...-1....2
%e ..4....3....1...-2....3...-4...-5....2....4....5....5...-1....3...-2...-1....1
%e ..4...-3...-3...-4...-2....2...-5...-1....4...-1....3....1...-1...-5....1....2
%e ..5...-5...-2....4....3...-2....3....4...-1...-3....4....2...-5....1...-5...-2
%e .-4....1....5...-4....2....4....4....4....4...-2...-4....1...-1....1...-5....4
%e .-1...-4....1...-4...-3....3...-3...-5...-3...-3...-1...-4...-2....2....4....2
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 25 2011
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