A158014 Primes p such that (p-1)/8 is also prime.

17, 41, 89, 137, 233, 569, 809, 857, 1049, 1097, 1193, 1433, 1913, 2153, 2777, 3209, 3449, 3593, 3833, 3929, 4073, 4457, 4793, 4937, 5273, 5417, 6089, 6473, 6569, 6857, 7433, 7529, 7577, 7817, 9209, 9497, 9833

Offset: 1

Author

Roger L. Bagula, Mar 11 2009

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A005385 for (p-1)/2, A090866 for (p-1)/4, A051644 for (p-1)/6, A055781 for (p-1)/10.

Programs

Mathematica

Flatten[Table[If[PrimeQ[n] && PrimeQ[(n - 1)/8], n, {}], {n, 1, 10000}]]
Select[Prime[Range[1500]], PrimeQ[(# - 1) / 8]&] (* Vincenzo Librandi, Apr 14 2013 *)

PARI

list(lim)=my(v=List()); forprime(p=2,(lim-1)\8, if(isprime(8*p+1), listput(v,8*p+1))); Vec(v) \\ Charles R Greathouse IV, Oct 20 2021

Formula

a(n)=8*A023228(n)+1. - R. J. Mathar, Mar 15 2009

a(n) >> n log^2 n. - Charles R Greathouse IV, Oct 21 2021

Extensions

Edited by the Associate Editors of the OEIS, Apr 22 2009