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A049580 Primes p such that x^48 = 2 has a solution mod p. 3
2, 23, 31, 47, 71, 89, 127, 167, 191, 223, 233, 239, 257, 263, 311, 359, 383, 431, 439, 479, 503, 599, 601, 647, 719, 727, 743, 839, 863, 881, 887, 911, 919, 983, 1031, 1103, 1151, 1223, 1289, 1319, 1327, 1367, 1399, 1423, 1433, 1439, 1471, 1487, 1511, 1559 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Complement of A212376 relative to A000040. - Vincenzo Librandi, Sep 14 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^48 - 2, p] == 0, x, Integers] =!= False; Select[Prime[Range[300]], ok] (* Vincenzo Librandi, Sep 14 2012 *)

PROG

(MAGMA) [p: p in PrimesUpTo(1600) | exists(t){x : x in ResidueClassRing(p) | x^48 eq 2}]; // Vincenzo Librandi, Sep 14 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, 48), print1(p, ", ")));

/* Joerg Arndt, Sep 21 2012 */

CROSSREFS

Cf. A000040, A212376.

Sequence in context: A049544 A049568 A049556 * A061448 A007510 A117242

Adjacent sequences:  A049577 A049578 A049579 * A049581 A049582 A049583

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified January 21 19:54 EST 2019. Contains 319350 sequences. (Running on oeis4.)