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A213050 Primes of the form 4*k+1 with primitive root +2. 2
5, 13, 29, 37, 53, 61, 101, 149, 173, 181, 197, 269, 293, 317, 349, 373, 389, 421, 461, 509, 541, 557, 613, 653, 661, 677, 701, 709, 757, 773, 797, 821, 829, 853, 877, 941, 1061, 1109, 1117, 1213, 1229, 1237, 1277, 1301, 1373, 1381, 1453, 1493, 1549, 1621 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Primes p such that both +2 and -2 are primitive roots mod p.

A001122 == A213050 union A213051.

LINKS

Table of n, a(n) for n=1..50.

MATHEMATICA

Select[Prime[Range[300]], Mod[#, 4] == 1 && PrimitiveRoot[#, 2] == 2&] (* Jean-Fran├žois Alcover, Jul 22 2018 *)

PROG

(PARI)

{ forprime (p=3, 10^4,

    rp = znorder(Mod(+2, p));

    rm = znorder(Mod(-2, p));

    if ( (rp==p-1) && (rm==p-1), print1(p, ", ") );

); }

CROSSREFS

Cf. A213051 (primes 4*k+3 with primitive root +2).

Cf. A001122 (primitive root +2), A007885 (primitive root +2 or -2).

Sequence in context: A261580 A007521 A294919 * A216822 A217466 A078598

Adjacent sequences:  A213047 A213048 A213049 * A213051 A213052 A213053

KEYWORD

nonn

AUTHOR

Joerg Arndt, Jun 03 2012

STATUS

approved

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Last modified July 13 13:48 EDT 2020. Contains 335688 sequences. (Running on oeis4.)