A269704 Numbers k such that prime(k) == 1 (mod 8).

7, 13, 21, 24, 25, 30, 33, 44, 51, 53, 55, 60, 65, 68, 71, 79, 80, 84, 87, 88, 98, 104, 106, 108, 110, 113, 116, 122, 135, 136, 140, 148, 152, 158, 159, 162, 165, 169, 174, 176, 184, 189, 191, 196, 197, 199, 204, 209, 211, 216, 218, 223, 227, 234, 237, 245

Offset

1,1

Comments

The asymptotic density of this sequence is 1/4 (by Dirichlet's theorem). - Amiram Eldar, Mar 01 2021

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(1) = 7 because prime(7) = 17 and 17 == 1 (mod 8).

Maple

Res:= NULL: count:= 0:
p:= 2:
for n from 2 while count < 100 do
  p:= nextprime(p);
  if p mod 8 = 1 then count:= count+1; Res:= Res, n fi
od:
Res; # Robert Israel, May 06 2019

Mathematica

Select[Range[300], Mod[Prime[#], 8] == 1 &]

Prog

(Magma) [n: n in [1..500] | NthPrime(n) mod 8 eq 1];
(PARI) lista(nn) = for(n=1, nn, if(Mod(prime(n), 8)==1, print1(n, ", "))); \\ Altug Alkan, Mar 04 2016

Crossrefs

The associated primes are in A007519.

Cf. similar sequences listed in A269703.

Sequence in context: A126621 A109331 A054858 * A157971 A135275 A304005

Adjacent sequences: A269701 A269702 A269703 * A269705 A269706 A269707

Keyword

nonn

Author

Vincenzo Librandi, Mar 04 2016

Status

approved