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A297674
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Greater of twin primes p such that 2^p-1 is prime.
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2
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5, 7, 13, 19, 31, 61, 1279, 4423, 110503, 132049, 20996011, 24036583
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OFFSET
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1,1
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COMMENTS
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Also 74207281 is a member, but its position is not known yet.
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LINKS
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MATHEMATICA
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twinPrimeBelowQ[n_]:=PrimeQ[n-2]
Table[MersennePrimeExponent[n], {n, 47}] // Select[twinPrimeBelowQ]
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PROG
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(PARI) is(n) = isprime(n)&&isprime(n-2)&&ispseudoprime(2^n-1)
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CROSSREFS
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KEYWORD
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nonn,hard,more
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AUTHOR
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STATUS
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approved
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