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A200457
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Number of -n..n arrays x(0..4) of 5 elements with zero sum and nonzero first and second differences
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1
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6, 144, 728, 2334, 5720, 12002, 22276, 38174, 61290, 93704, 137374, 194964, 268842, 362092, 477620, 618954, 789324, 992970, 1233412, 1515270, 1842742, 2220844, 2654034, 3148080, 3707758, 4339192, 5047836, 5840186, 6721964, 7700510, 8781768
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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) = -a(n-1) +a(n-3) +2*a(n-4) +2*a(n-5) +a(n-6) -a(n-8) -a(n-9) -a(n-10) -2*a(n-11) -2*a(n-12) -2*a(n-13) -a(n-14) +a(n-15) +2*a(n-16) +2*a(n-17) +2*a(n-18) +a(n-19) +a(n-20) +a(n-21) -a(n-23) -2*a(n-24) -2*a(n-25) -a(n-26) +a(n-28) +a(n-29)
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EXAMPLE
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Some solutions for n=3
.-1....0...-2...-1....3....3...-1....1...-2...-2....1...-2...-2....3...-3....0
..2...-2...-1....0...-2...-1....1...-3....1....1....3....0....3...-1....3...-2
.-2...-3....1...-2....0....3...-3....1...-1...-1...-3....1....1....2...-1....2
..1....3....0....3....1...-3....3...-1....3....2....0...-1....0...-3....3...-3
..0....2....2....0...-2...-2....0....2...-1....0...-1....2...-2...-1...-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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