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A090872
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a(n) is the smallest number m greater than 1 such that m^(2^k)+1 for k=0,1,...,n are primes.
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10
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OFFSET
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0,1
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COMMENTS
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The first five terms of this sequence correspond to Fermat primes.
Note that 7072833120 is not the smallest base to give at least six possibly nonconsecutive k values. For example, 292582836^(2^k) + 1 is prime for k = 0,1,2,3,4,7. - Jeppe Stig Nielsen, Sep 18 2022
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LINKS
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EXAMPLE
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a(5)=7072833120 because 7072833120^2^k+1 for k=0,1,2,3,4,5 are 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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