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A065117
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Primes such that prime(p) +- pi(p) are simultaneously prime.
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1
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3, 113, 463, 593, 743, 1109, 2473, 4139, 4657, 4937, 5531, 5879, 6473, 6581, 6659, 6701, 7297, 7529, 8387, 8521, 8929, 9349, 10369, 10499, 12289, 12829, 13411, 13697, 14033, 14323, 15907, 18637, 19391, 19841, 21143, 21647, 23021, 27077
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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113 is in the sequence because PrimePi(113) is 30, Prime(113) is 617, and both 587 and 647 are primes.
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MATHEMATICA
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Do[p0 = Prime[ Prime[n]]; p1 = PrimePi[ Prime[n]]; If[ PrimeQ[p0 + p1] && PrimeQ[p0 - p1], Print[ Prime[n]]], {n, 1, 5000} ]
spQ[n_]:=Module[{p=PrimePi[n]}, AllTrue[Prime[n]+{p, -p}, PrimeQ]]; Select[ Prime[ Range[10000]], spQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 03 2018 *)
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PROG
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(PARI) { n=0; default(primelimit, 4294965247); for (m=1, 10^9, p=prime(m); p0 = prime(p); p1 = primepi(p); if (isprime(p0 + p1) && isprime(p0 - p1), write("b065117.txt", n++, " ", p); if (n==1000, return)) ) } \\ Harry J. Smith, Oct 10 2009
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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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