12 lines
403 B
Markdown
12 lines
403 B
Markdown
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It was proposed by Christian Goldbach that every odd composite number can be written as the sum of a prime and twice a square.
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`9 = 7 + 2 * 1^2`
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`15 = 7 + 2 * 2^2`
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`21 = 3 + 2 * 3^2`
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`25 = 7 + 2 * 3^2`
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`27 = 19 + 2 * 2^2`
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`33 = 31 + 2 * 1^2`
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It turns out that the conjecture was false.
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What is the smallest odd composite that cannot be written as the sum of a prime and twice a square?
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