A049592 - OEIS

A049592

Primes p such that x^60 = 2 has a solution mod p.

2, 23, 47, 89, 113, 127, 167, 223, 233, 239, 257, 263, 353, 359, 383, 431, 439, 479, 503, 593, 599, 617, 647, 719, 727, 743, 839, 863, 887, 911, 919, 983, 1049, 1097, 1103, 1193, 1217, 1223, 1289, 1319, 1327, 1367, 1399, 1423, 1433, 1439, 1487, 1553

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OFFSET

1,1

COMMENTS

Complement of A059645 relative to A000040. - Vincenzo Librandi, Sep 15 2012

LINKS

R. J. Mathar, Table of n, a(n) for n = 1..1000

Index entries for related sequences

MATHEMATICA

ok[p_]:= Reduce[Mod[x^60 - 2, p] == 0, x, Integers] =!= False; Select[Prime[Range[250]], ok] (* Vincenzo Librandi, Sep 15 2012 *)

PROG

(Magma) [p: p in PrimesUpTo(1600) | exists(t){x : x in ResidueClassRing(p) | x^60 eq 2}]; // Vincenzo Librandi, Sep 15 2012

(PARI)

N=10^4; default(primelimit, N);

ok(p, r, k)={ return ( (p==r) || (Mod(r, p)^((p-1)/gcd(k, p-1))==1) ); }

forprime(p=2, N, if (ok(p, 2, 60), print1(p, ", ")));

/* Joerg Arndt, Sep 21 2012 */

CROSSREFS

Cf. A000040, A059645.

Sequence in context: A325145 A105440 A139831 * A054679 A057621 A074809

Adjacent sequences: A049589 A049590 A049591 * A049593 A049594 A049595

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved