login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 (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 - 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 18 00:56 EST 2021. Contains 340249 sequences. (Running on oeis4.)