cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A060503 Primes p that have a primitive root between 0 and p that is not a primitive root of p^2.

Original entry on oeis.org

2, 29, 37, 43, 71, 103, 109, 113, 131, 181, 191, 211, 257, 263, 269, 283, 349, 353, 359, 367, 373, 397, 439, 449, 461, 487, 509, 563, 599, 617, 619, 631, 641, 647, 653, 701, 739, 743, 773, 797, 839, 857, 863, 883, 887, 907, 919, 947, 971, 983, 1019, 1031
Offset: 1

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Author

Jud McCranie, Mar 22 2001

Keywords

Comments

The smallest primitive roots of p that are not primitive roots of p^2 are in A060504.
Except for the initial term 2, this is a subsequence of A134307. - Jeppe Stig Nielsen, Jul 31 2015

Examples

			14 is a primitive root of 29 but not of 29^2, so 29 is a term.
		

Crossrefs

Programs

  • Maple
    filter:= proc(p) local x;
      if not isprime(p) then return false fi;
      x:= 0;
      do
        x:= numtheory:-primroot(x,p);
        if x = FAIL then return false fi;
        if x &^ (p-1) mod p^2 = 1 then return true fi;
      od
    end proc:
    select(filter, [2, seq(i,i=3..2000,2)]); # Robert Israel, Dec 01 2016
  • Mathematica
    Reap[For[p = 2, p < 1100, p = NextPrime[p], prp = PrimitiveRootList[p]; prp2 = Select[PrimitiveRootList[p^2], # <= Last[prp]&]; If[AnyTrue[prp, FreeQ[prp2, #]&], Print[p]; Sow[p]]]][[2, 1]] (* Jean-François Alcover, Feb 26 2019 *)
  • PARI
    forprime(p=2,,for(a=1,p-1,if(znorder(Mod(a,p))==p-1&Mod(a,p^2)^(p-1)==1,print1(p,", ");break()))) \\ Jeppe Stig Nielsen, Jul 31 2015