A157977 Primes p such that 20*p + 19 is also prime.

2, 3, 11, 17, 23, 29, 41, 71, 101, 149, 167, 233, 239, 251, 263, 269, 281, 293, 317, 347, 353, 401, 449, 461, 491, 503, 557, 563, 569, 647, 683, 743, 797, 857, 941, 947, 953, 977, 1019, 1031, 1091, 1103, 1151, 1163, 1193, 1217, 1283, 1289, 1319, 1361, 1373

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..2000

Mathematica

q=19; lst={}; Do[p=Prime[n]; If[PrimeQ[(q+1)*p+q], AppendTo[lst, p]], {n, 6!}]; lst
Select[Prime[Range[250]], PrimeQ[20#+19]&] (* Harvey P. Dale, Jul 04 2011 *)

Prog

(Magma) [n: n in [0..2000] | IsPrime(n) and IsPrime(20*n + 19)]; // Vincenzo Librandi, Feb 03 2014

Crossrefs

Cf. A136082, A136083, A023213, A023221, A023235, A023240, A157974, A136083, A136084, A136085, A136086, A136087, A089440, A157975, A157976.

Sequence in context: A242256 A189483 A164952 * A105903 A045338 A250175

Adjacent sequences: A157974 A157975 A157976 * A157978 A157979 A157980

Keyword

nonn,easy

Author

Vladimir Joseph Stephan Orlovsky, Mar 10 2009

Status

approved