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A023230 Numbers k such that k and 8*k + 5 are both prime. 8
3, 7, 13, 19, 43, 67, 103, 109, 127, 139, 151, 181, 193, 199, 211, 223, 241, 277, 283, 349, 379, 397, 421, 433, 439, 463, 577, 601, 607, 613, 619, 727, 733, 787, 829, 853, 883, 967, 991, 1033, 1039, 1117, 1201, 1237, 1291, 1303, 1399, 1429, 1459, 1531, 1567, 1579 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

MATHEMATICA

lst={}; Do[p=Prime[n]; If[PrimeQ[8*p+5], AppendTo[lst, p]], {n, 6!}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 16 2009 *)

Select[Prime [Range[0, 300]], PrimeQ[8# + 5] &] (* Vincenzo Librandi, Sep 25 2012 *)

PROG

(MAGMA) [ p: p in PrimesUpTo(1580) | IsPrime(8*p+5) ]; // Klaus Brockhaus, Dec 21 2008

(PARI) select(p->isprime(8*p+5), primes(1000)) \\ Charles R Greathouse IV, Sep 25 2012

CROSSREFS

Cf. A007521 (primes of form 8n+5), A105133 (numbers n such that 8n+5 is prime).

Sequence in context: A252091 A217035 A134765 * A194581 A106080 A187819

Adjacent sequences:  A023227 A023228 A023229 * A023231 A023232 A023233

KEYWORD

nonn,easy

AUTHOR

David W. Wilson

STATUS

approved

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Last modified July 27 20:33 EDT 2021. Contains 346308 sequences. (Running on oeis4.)