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A171139
Primes p such that 7*p^2+7*p-1 is also prime.
5
2, 3, 17, 19, 23, 29, 47, 67, 73, 97, 113, 151, 163, 173, 223, 227, 229, 239, 251, 257, 263, 311, 331, 359, 367, 373, 389, 409, 419, 433, 439, 457, 463, 491, 503, 523, 541, 563, 569, 607, 701, 733, 809, 853, 877, 883, 941, 953, 967, 983, 1013, 1033, 1049
OFFSET
1,1
LINKS
MATHEMATICA
Select[Prime[Range[200]], PrimeQ[7 #^2 + 7 # - 1]&] (* Vincenzo Librandi, Apr 16 2013 *)
PROG
(Magma) [p: p in PrimesUpTo(1050) | IsPrime(7*p^2+7*p-1)]; // Vincenzo Librandi, Apr 16 2013
CROSSREFS
Cf. A171138.
Sequence in context: A361104 A090913 A176236 * A291281 A135931 A215323
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jan 26 2010
STATUS
approved