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A057663
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Primes p such that p+2^p is also a prime.
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3
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OFFSET
| 1,1
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COMMENTS
| Different from A056206, where e.g. at n=89, 89 is not minimal, A056206(89)=29 and not 89.
a(6) > 27479 - Ralf Stephan (ralf(AT)ark.in-berlin.de), Oct 23 2002
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EXAMPLE
| q=3, 2^3+3 = 11 a prime.
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MATHEMATICA
| f[p_]:=2^p+p; lst={}; Do[p=Prime[n]; If[PrimeQ[f[p]], Print[p]; AppendTo[lst, p]], {n, 2*6!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Sep 22 2009]
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PROG
| (PARI) \ p^q + q is prime q is prime ptoqpq2(p, n)= { local(x, y, q); for(x=1, n, q=prime(x); y=p^q+q; if(ispseudoprime(y), print1(q", ")) ) } (Cino Hilliard)
(MAGMA) [p: p in PrimesUpTo(1000) | IsPrime(2^p+p) ] [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 07 2010]
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CROSSREFS
| Cf. A056206, A056208, A057664, A057665.
Sequence in context: A144617 A107655 A133660 * A056244 A173487 A103081
Adjacent sequences: A057660 A057661 A057662 * A057664 A057665 A057666
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KEYWORD
| nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Oct 16 2000
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