

A153419


Primes p such that p+20 is also prime.


7



3, 11, 17, 23, 41, 47, 53, 59, 83, 89, 107, 131, 137, 173, 179, 191, 251, 257, 263, 293, 311, 317, 347, 353, 359, 389, 401, 419, 443, 467, 479, 503, 521, 557, 587, 593, 599, 641, 653, 719, 809, 839, 857, 863, 887, 947, 971, 977, 1013, 1019, 1031, 1049, 1097
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OFFSET

1,1


LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..10000 (first 1000 terms from Vincenzo Librandi)


EXAMPLE

3 is in the sequence because 3+20=23 is prime; 11 is in the sequence because 11+20=31 is prime.


MATHEMATICA

lst={}; d=20; Do[p=Prime[n]; If[PrimeQ[p+d], AppendTo[lst, p]], {n, 6!}]; lst
Select[Prime[Range[200]], PrimeQ[(# + 20)]&] (* Vincenzo Librandi, Apr 14 2013 *)


PROG

(MAGMA) [p: p in PrimesUpTo(1100)  IsPrime(p + 20)]; // Vincenzo Librandi, Apr 14 2013


CROSSREFS

Cf. A153417, A049488, A153418.
Sequence in context: A038960 A019397 A108328 * A079020 A118590 A136082
Adjacent sequences: A153416 A153417 A153418 * A153420 A153421 A153422


KEYWORD

nonn,easy


AUTHOR

Vladimir Joseph Stephan Orlovsky, Dec 25 2008


EXTENSIONS

Definition improved from Bruno Berselli, Oct 31 2012


STATUS

approved



