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A112722
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First n-digit number m such that sigma(m) is prime.
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0
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2, 16, 289, 1681, 10201, 146689, 1190281, 10374841, 103042801, 1023424081, 10009802401, 100019755081, 1000242014641, 10001235475729, 100001580006241, 1000017101564209, 10000044600049729, 100000569832596889
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OFFSET
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1,1
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COMMENTS
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Each term is of the form p^k where p is prime. For n > 1, k is even.
Can it be proved that a(n) exists for all n?
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LINKS
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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