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A199851
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Number of -n..n arrays x(0..6) of 7 elements with zero sum and no element more than one greater than the previous
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1
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153, 575, 1393, 2958, 5754, 10426, 17879, 29268, 46126, 70322, 104253, 150764, 213380, 296204, 404213, 543086, 719592, 941366, 1217343, 1557506, 1973400, 2477778, 3085247, 3811830, 4675676, 5696580, 6896795, 8300422, 9934376
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 2*a(n-1) -a(n-3) -a(n-5) +a(n-6) -2*a(n-7) +2*a(n-8) +a(n-9) -a(n-13) -2*a(n-14) +2*a(n-15) -a(n-16) +a(n-17) +a(n-19) -2*a(n-21) +a(n-22) for n>24
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EXAMPLE
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Some solutions for n=6
..5....5....4....4....2....1....5....4....3....0....4....2....5....6....5....3
..4....6....3...-1....3....1....4....5....1....0....4....3....4....5....5....1
..0....2....3....0....1....2....4....3...-1....1...-2....4....4....3....4....1
..0....2...-1....0...-1....2....2...-3....0....2...-1....0....2....3...-5....1
.-2...-5....0....0....0...-2...-3...-2...-1....1....0....1...-5...-5...-4....0
.-3...-5...-5....0...-3...-1...-6...-1....0....0...-2...-5...-5...-6...-3...-3
.-4...-5...-4...-3...-2...-3...-6...-6...-2...-4...-3...-5...-5...-6...-2...-3
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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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