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A161719
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Least number k such that 7^(2^i) + k is prime for i = 0,1,..,n-1.
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0
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OFFSET
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1,1
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LINKS
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EXAMPLE
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a(5) = 990 because k = 990 is the minimal k such that N = 7^(2^i) + k is prime for i = 0, 1, 2, 3, 4; N = 997, 1039, 3391, 5765791, 33232930570591. But 7^(2^5) + 990 is divisible by 37 and four other primes.
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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