

A040147


Primes p such that x^4 = 20 has a solution mod p.


3



2, 5, 11, 19, 29, 31, 59, 61, 71, 79, 131, 139, 151, 179, 191, 199, 211, 229, 239, 251, 271, 311, 331, 349, 359, 379, 401, 409, 419, 421, 431, 439, 449, 479, 491, 499, 509, 521, 569, 571, 599, 619, 631, 659, 661
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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  20, p]== 0, x, Integers]=!= False; Select[Prime[Range[180]], ok] (* Vincenzo Librandi, Sep 12 2012 *)


PROG

(MAGMA) [p: p in PrimesUpTo(800)  exists(t){x : x in ResidueClassRing(p)  x^4 eq 20}]; // Vincenzo Librandi, Sep 12 2012


CROSSREFS

Cf. A040148.
Sequence in context: A045363 A336116 A031870 * A152471 A088796 A190309
Adjacent sequences: A040144 A040145 A040146 * A040148 A040149 A040150


KEYWORD

nonn,easy


AUTHOR

N. J. A. Sloane.


STATUS

approved



