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A064402
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Numbers n such that prime(n)+n is a prime, where prime(n) denotes the n-th prime number.
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19
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1, 2, 4, 6, 18, 22, 24, 26, 32, 34, 42, 48, 66, 70, 72, 82, 92, 96, 98, 100, 102, 104, 106, 108, 114, 116, 126, 130, 144, 150, 152, 158, 172, 180, 200, 202, 204, 206, 218, 222, 228, 236, 270, 282, 290, 300, 312, 322, 324, 328, 330, 350, 352, 356, 362, 378, 384
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OFFSET
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1,2
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COMMENTS
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a(n) = order among the primes of A061067(n).
Except for the first one all terms are even. Conjecture: First differences include all even integers. - Zak Seidov, Nov 10 2013
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LINKS
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FORMULA
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MATHEMATICA
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Select[ Range[ 400 ], PrimeQ[ Prime[ # ] + # ] & ]
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PROG
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(PARI) { n=0; for (m=1, 10^9, if (isprime(prime(m) + m), write("b064402.txt", n++, " ", m); if (n==1000, break)) ) } \\ Harry J. Smith, Sep 13 2009
(Magma) [n: n in [0..500]| IsPrime(NthPrime(n) +n)]; // Vincenzo Librandi, Apr 06 2011
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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