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A064403 Prime(n) + n and prime(n) - n are both primes. 9
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Starting with 6 all terms are == 0 mod 6. - Zak Seidov, Jan 04 2013

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..1000

EXAMPLE

4 is in the sequence because the fourth prime is 7 and both 7+4 and 7-4 are primes.

MATHEMATICA

Select[ Range[ 4000 ], PrimeQ[ Prime[ # ] + # ] && PrimeQ[ Prime[ # ] - # ] & ]; Join[{4}, Select[ Range[6, 4000, 6 ], PrimeQ[Prime[ # ] + # ] && PrimeQ[ Prime[ # ] - # ] & ]] (* Zak Seidov, Jan 04 2013 *)

PROG

(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]

CROSSREFS

Sequence in context: A107390 A051253 A175955 * A235344 A060667 A218065

Adjacent sequences:  A064400 A064401 A064402 * A064404 A064405 A064406

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Sep 28 2001

STATUS

approved

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Last modified November 26 07:08 EST 2014. Contains 250020 sequences.