A171832 Primes p such that p and 5*p^2+5*p-1 are both prime.
2, 3, 5, 11, 29, 41, 47, 137, 197, 227, 251, 269, 293, 353, 359, 383, 401, 467, 641, 659, 701, 797, 839, 857, 929, 1103, 1163, 1193, 1229, 1259, 1289, 1319, 1373, 1439, 1451, 1487, 1523, 1553, 1559, 1721, 1787, 1847, 1871, 1877, 1889, 1913, 1949, 2081
Offset: 1
Keywords
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..3000
Programs
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Magma
[p: p in PrimesUpTo(2500) | IsPrime(5*p^2+5*p-1)]; // Vincenzo Librandi, Aug 20 2014
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Mathematica
Select[Prime[Range[400]],PrimeQ[5#^2+5#-1]&] (* Harvey P. Dale, Apr 03 2010 *)
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PARI
lista(nn) = {forprime(p=2, nn, if (isprime(5*p^2+5*p-1), print1(p, ", ")););} \\ Michel Marcus, Aug 20 2014
Extensions
Corrected sequence because 1553 had been omitted Harvey P. Dale, Apr 03 2010