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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A042973 Primes p such that x^7 = 5 has no solution mod p. 2
29, 43, 113, 127, 197, 211, 239, 281, 337, 379, 421, 449, 463, 491, 547, 617, 631, 659, 673, 701, 743, 757, 911, 953, 967, 1009, 1051, 1093, 1163, 1289, 1373, 1429, 1471, 1499, 1583, 1597, 1667, 1709, 1723, 1877, 1933, 2003, 2017, 2087 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Complement of A216882 relative to A000040. - Vincenzo Librandi, Sep 19 2012

LINKS

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

MATHEMATICA

ok[p_]:= Reduce[Mod[x^7 - 5, p] == 0, x, Integers] == False; Select[Prime[Range[800]], ok] (* Vincenzo Librandi, Sep 19 2012  *)

PROG

(MAGMA) [p: p in PrimesUpTo(2500) | not exists{x : x in ResidueClassRing(p) | x^7 eq 5} ]; // Vincenzo Librandi, Sep 19 2012

CROSSREFS

Sequence in context: A039348 A043171 A043951 * A323628 A020997 A108280

Adjacent sequences:  A042970 A042971 A042972 * A042974 A042975 A042976

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 September 25 23:58 EDT 2021. Contains 347664 sequences. (Running on oeis4.)