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A064403
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Prime(n) + n and prime(n) - n are both primes.
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9
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4, 6, 18, 42, 66, 144, 282, 384, 408, 450, 522, 564, 618, 672, 720, 732, 744, 828, 858, 1122, 1308, 1374, 1560, 1644, 1698, 1776, 1848, 1920, 2022, 2304, 2412, 2616, 2766, 2778, 2874, 2958, 2970, 3036, 3042, 3240, 3258, 3354, 3360, 3432, 3540, 3594, 3732
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OFFSET
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1,1
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COMMENTS
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Starting with 6 all terms are == 0 mod 6. - Zak Seidov, Jan 04 2013
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LINKS
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Harry J. Smith, Table of n, a(n) for n = 1..1000
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EXAMPLE
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4 is in the sequence because the fourth prime is 7 and both 7+4 and 7-4 are primes.
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MATHEMATICA
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Select[ Range[ 4000 ], PrimeQ[ Prime[ # ] + # ] && PrimeQ[ Prime[ # ] - # ] & ]; Join[{4}, Select[ Range[6, 4000, 6 ], PrimeQ[Prime[ # ] + # ] && PrimeQ[ Prime[ # ] - # ] & ]] (* Zak Seidov, Jan 04 2013 *)
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PROG
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(PARI) { n=0; default(primelimit, 1800000); for (m=1, 10^9, if (isprime(prime(m) + m) && isprime(prime(m) - m), write("b064403.txt", n++, " ", m); if (n==1000, break)) ) } [From Harry J. Smith, Sep 13 2009]
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CROSSREFS
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Sequence in context: A107390 A051253 A175955 * A060667 A218065 A005959
Adjacent sequences: A064400 A064401 A064402 * A064404 A064405 A064406
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KEYWORD
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nonn
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AUTHOR
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Robert G. Wilson v, Sep 28 2001
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STATUS
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approved
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