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A256451
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Numbers n such that 10^n + prime(n) is prime.
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0
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OFFSET
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1,1
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COMMENTS
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a(11) > 10^5. - Robert Price, Mar 29 2015
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LINKS
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Table of n, a(n) for n=1..10.
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EXAMPLE
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4 is in this sequence since the fourth prime is 7 and 10^4+7=10007 is prime.
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MATHEMATICA
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Select[Range[100000], PrimeQ[10^# + Prime[#]] &]
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PROG
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(PARI) for(n=1, 10^3, if(ispseudoprime(10^n+prime(n)), print1(n, ", "))) \\ Derek Orr, Mar 29 2015
(MAGMA) [n: n in [1..770] | IsPrime(NthPrime(n) + 10^n)]; // Vincenzo Librandi, Mar 30 2015
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CROSSREFS
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Cf. A110065, A110066, A110067.
Sequence in context: A104465 A175759 A098515 * A059719 A264930 A226347
Adjacent sequences: A256448 A256449 A256450 * A256452 A256453 A256454
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KEYWORD
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nonn,hard,more
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AUTHOR
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Robert Price, Mar 29 2015
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STATUS
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approved
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