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A023235
Primes p such that 9*p + 8 is also prime.
20
5, 7, 11, 19, 29, 47, 61, 71, 79, 89, 97, 107, 127, 131, 139, 151, 167, 179, 181, 211, 229, 251, 271, 317, 337, 397, 401, 419, 421, 449, 461, 467, 487, 541, 547, 557, 571, 599, 601, 607, 659, 677, 701, 709, 727, 739, 761, 811, 827, 839, 877, 881, 907, 929, 971, 1051
OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
MATHEMATICA
lst={}; Do[p=Prime[n]; If[PrimeQ[9*p+8], AppendTo[lst, p]], {n, 6!}]; lst (* Vladimir Joseph Stephan Orlovsky, Mar 10 2009 *)
Select[Prime[Range[900]], PrimeQ[9 # + 8] &] (* Vincenzo Librandi, May 21 2014 *)
PROG
(Magma) [n: n in [0..1000] | IsPrime(n) and IsPrime(9*n+8)]; // Vincenzo Librandi, Nov 20 2010
(PARI) is(n)=isprime(9*n+8) && isprime(n) \\ Charles R Greathouse IV, Jul 02 2013
(Magma) [p: p in PrimesUpTo(1100)| IsPrime(9*p+8)]; // Vincenzo Librandi, May 21 2014
CROSSREFS
Sequence in context: A182121 A072825 A045440 * A118918 A019376 A159080
KEYWORD
nonn,easy
STATUS
approved