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%I
%S 1,7,47,285,1905,13635,99143,734607,5477087,40989699,307950303,
%T 2320964021,17543356961,132967038437,1010302510909,7693410001853,
%U 58699664900479,448643950237839,3434254414420963,26324281838259421
%N Number of zero-sum -6..6 arrays of n elements with first and second differences also in -6..6
%C Column 6 of A201873
%H R. H. Hardin, <a href="/A201871/b201871.txt">Table of n, a(n) for n = 1..210</a>
%e Some solutions for n=7
%e .-2....2....4....2...-5....1...-1...-1....2...-3....4...-3...-1...-2...-5....3
%e .-2....2....2....0...-2....3....2....2....4...-3....6...-1...-4....4...-1....5
%e ..4...-2....2....0....0....1....0....2....1....2....4....3...-3....6....2....2
%e ..4...-3....1...-2....4....2...-2....0...-2....2....0....2...-2....2....3...-2
%e ..1....0....0....2....3....0....2....1...-4....0...-3....2....2...-3....0...-3
%e ..0....2...-5....1....0...-1....2....1...-1....1...-6....0....4...-4...-1...-2
%e .-5...-1...-4...-3....0...-6...-3...-5....0....1...-5...-3....4...-3....2...-3
%K nonn
%O 1,2
%A _R. H. Hardin_ Dec 06 2011
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