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A040138 Primes p such that x^4 = 17 has a solution mod p. 2
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified September 17 22:53 EDT 2019. Contains 327147 sequences. (Running on oeis4.)