login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A040113 Primes p such that x^4 = 7 has no solution mod p. 1

%I #9 Sep 08 2022 08:44:53

%S 5,11,13,17,23,41,43,53,61,67,71,73,79,89,97,101,107,127,137,149,151,

%T 157,163,173,179,181,191,197,211,229,233,239,241,257,263,269,277,281,

%U 293,313,317,331,337,347,349,353

%N Primes p such that x^4 = 7 has no solution mod p.

%C Complement of A040112 relative to A000040. - _Vincenzo Librandi_, Sep 17 2012

%H Vincenzo Librandi, <a href="/A040113/b040113.txt">Table of n, a(n) for n = 1..1000</a>

%t ok[p_]:= Reduce[Mod[x^4 - 7, p] == 0, x, Integers] == False;Select[Prime[Range[100]], ok] (* _Vincenzo Librandi_, Sep 17 2012 *)

%o (Magma) [p: p in PrimesUpTo(500) | not exists{x : x in ResidueClassRing(p) | x^4 eq 7} ]; // _Vincenzo Librandi_, Sep 17 2012

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_.

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 23 16:40 EDT 2024. Contains 371916 sequences. (Running on oeis4.)