A045473 Primes congruent to 6 mod 7.

13, 41, 83, 97, 139, 167, 181, 223, 251, 293, 307, 349, 419, 433, 461, 503, 587, 601, 643, 727, 769, 797, 811, 839, 853, 881, 937, 1021, 1049, 1063, 1091, 1217, 1231, 1259, 1301, 1399, 1427, 1483, 1511, 1553, 1567, 1609, 1637, 1693, 1721, 1777, 1847, 1861

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Comments

Conjecture: Primes p such that ((x+1)^7-1)/x has 3 irreducible factors of degree 2 over GF(p). - Federico Provvedi, Mar 31 2018

Also primes of the form 14*k + 13. - David A. Corneth, Apr 02 2018

Links

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

Crossrefs

Cf. A042988 (complement).

Programs

GAP

Filtered([1..1900],n->IsPrime(n) and n mod 7 = 6); # Muniru A Asiru, Mar 31 2018

Magma

[ p: p in PrimesUpTo(11000) | p mod 7 eq 6 ]; // Vincenzo Librandi, Aug 13 2012

Maple

select(n->isprime(n) and modp(n,7)=6,[$1..1900]); # Muniru A Asiru, Mar 31 2018

Mathematica

Select[Range[6,1600,7],PrimeQ] (* Bruno Berselli, Aug 17 2012 *)

PARI

is(n)=isprime(n) && n%7==6 \\ Charles R Greathouse IV, Jul 01 2016