A040138 - OEIS

A040138

Primes p such that x^4 = 17 has a solution mod p.

2, 17, 19, 43, 47, 59, 67, 83, 103, 127, 149, 151, 157, 179, 191, 223, 229, 239, 251, 257, 263, 271, 293, 307, 331, 353, 359, 383, 389, 409, 433, 443, 457, 463, 467, 491, 509, 523, 563, 587, 599, 613, 631, 647

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OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

MATHEMATICA

ok [p_]:=Reduce[Mod[x^4 - 17, p]== 0, x, Integers]=!= False; Select[Prime[Range[180]], ok] (* Vincenzo Librandi, Sep 12 2012 *)

PROG

(Magma) [p: p in PrimesUpTo(800) | exists{x: x in ResidueClassRing(p) | x^4 eq 17}]; // Vincenzo Librandi, Sep 12 2012

(PARI) /* with workaround for bug with ispower( Mod(17, n), 4) "division by zero" */

select( n->(n==2) || (ispower( Mod(17, n), 4)), primes(1000) )

/* Joerg Arndt, Sep 12 2012 */

CROSSREFS

Cf. A040140.

Sequence in context: A041339 A042925 A019413 * A240475 A107139 A042055

Adjacent sequences: A040135 A040136 A040137 * A040139 A040140 A040141

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved