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A183939
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Number of strings of n numbers x(i) in -4..4 with sums of x(i) and of x(i)*x(i+1) both zero
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1
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1, 1, 9, 33, 321, 1411, 10613, 70449, 534153, 3908739, 31172293, 247959153, 2040991681, 16818777105, 139873091535, 1164007471357, 9753589044027, 82147216112609, 696523301660651, 5930891437147689, 50682977439086169
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OFFSET
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1,3
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COMMENTS
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LINKS
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EXAMPLE
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Some solutions for n=6
..0....3...-2....4....0...-1....1...-4....4....4...-2....0...-1....4....2....3
.-3...-2....0....0...-3....0....2....1....0....1...-1....4....2...-1...-1....2
..0...-2....3....0...-3....0...-1...-4....1....2....2....0....1....2....2...-1
..2...-2....2...-3....3...-2....0....1...-4...-3....1....0....0....0....1...-1
..3...-1...-3...-4....0....0...-2....4...-1....0...-1....0....0...-3...-1....1
.-2....4....0....3....3....3....0....2....0...-4....1...-4...-2...-2...-3...-4
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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