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A110931
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Numbers k such that 2*k^k - 1 is prime.
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7
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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3 is in the sequence since 2*3^3 - 1 = 53 is prime.
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MATHEMATICA
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PROG
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(PARI) for(n=1, 2000, 1; if(isprime(2*n^n-1), print(n))) \\ Ray G. Opao, Oct 23 2014
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CROSSREFS
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Numbers k such that b*k^k - b + 1 is prime: this sequence (b=2), A301521 (b=4), A302123 (b=6).
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KEYWORD
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more,nonn,hard
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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