A045473 - OEIS

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

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OFFSET

1,1

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

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 *)

PROG

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

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

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

CROSSREFS

Cf. A042988 (complement).

Sequence in context: A043162 A043942 A004624 * A102083 A139866 A026918

Adjacent sequences: A045470 A045471 A045472 * A045474 A045475 A045476

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved