login
A049584
Primes p such that x^52 = 2 has a solution mod p.
2
2, 7, 23, 31, 47, 71, 73, 89, 103, 113, 127, 151, 167, 191, 199, 223, 233, 239, 257, 263, 271, 281, 311, 337, 353, 359, 367, 383, 431, 439, 463, 479, 487, 503, 577, 593, 601, 607, 617, 631, 647, 719, 727, 743, 751, 823, 839, 863, 881, 887, 919, 967, 983, 991
OFFSET
1,1
COMMENTS
Complement of A059641 relative to A000040. - Vincenzo Librandi, Sep 14 2012
MATHEMATICA
ok[p_]:= Reduce[Mod[x^52 - 2, p] == 0, x, Integers] =!= False; Select[Prime[Range[300]], ok] (* Vincenzo Librandi, Sep 14 2012 *)
PROG
(Magma) [p: p in PrimesUpTo(1000) | exists(t){x : x in ResidueClassRing(p) | x^52 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, 52), print1(p, ", ")));
/* Joerg Arndt, Sep 21 2012 */
CROSSREFS
Sequence in context: A072935 A049564 A072936 * A045382 A049560 A049588
KEYWORD
nonn,easy
STATUS
approved