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A202506
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Number of zero-sum -3..3 arrays of n elements with first through third differences also in -3..3
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1
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1, 3, 15, 29, 95, 255, 747, 2215, 6649, 19967, 60145, 182003, 554625, 1691547, 5175093, 15875649, 48789933, 150258301, 463501341, 1431832723, 4429155217, 13716674493, 42524970155, 131966196475, 409893633219, 1274208141011
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OFFSET
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1,2
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COMMENTS
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LINKS
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EXAMPLE
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Some solutions for n=7
.-3...-1...-1...-3....0...-1...-2...-1....2....0....3....0...-3....0....0...-1
.-2....0...-1...-1....0...-1....1....1....0...-1....1...-1....0....0....0....2
.-1....0...-1...-1...-1...-1....1....1...-2....0...-1...-1....1...-1....0....2
.-1...-1....0....0...-1....0....1....0...-2....0...-3....1....1...-2...-1....1
..1...-1....1....1....0....1....0...-1...-1....0...-2....2....1...-1....0....0
..3....0....2....2....1....1....0...-1....1....0....0....1....0....1....1...-2
..3....3....0....2....1....1...-1....1....2....1....2...-2....0....3....0...-2
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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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