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A363069
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Size of the largest subset of {1,2,...,n} such that no two elements sum to a perfect square.
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0
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1, 1, 1, 2, 2, 3, 4, 4, 4, 4, 5, 5, 6, 6, 6, 7, 8, 8, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 18, 19, 19, 19, 20, 20, 20, 20, 21, 21, 22, 22, 23, 23, 24, 24, 25, 25, 25, 25, 26, 26, 26, 26, 26, 27, 27
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OFFSET
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1,4
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LINKS
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FORMULA
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The set: {k | k <= n, k == 1 (mod 3)} provides a lower bound: a(n) >= floor((n+2)/3).
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EXAMPLE
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The first few examples where a(n) increases are {1}, {1,4}, {1,4,6}, and {1,4,6,7}.
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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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