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.

Showing 1-3 of 3 results.

A059362 Primes p such that x^24 = 2 has no solution mod p.

Original entry on oeis.org

3, 5, 7, 11, 13, 17, 19, 29, 37, 41, 43, 53, 59, 61, 67, 73, 79, 83, 97, 101, 103, 107, 109, 113, 131, 137, 139, 149, 151, 157, 163, 173, 179, 181, 193, 197, 199, 211, 227, 229, 241, 251, 269, 271, 277, 281, 283, 293, 307, 313, 317, 331, 337, 347, 349, 353, 367
Offset: 1

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Author

Klaus Brockhaus, Jan 27 2001

Keywords

Comments

Complement of A049556 relative to A000040.
Coincides for the first 23 terms with sequence A059264 of primes p such that x^12 = 2 has no solution mod p (first divergence is at 113, cf. A059331).
Coincides for the first 161 terms with sequence A212376 of primes p such that x^48 = 2 has no solution mod p (first divergence is at 1217, cf. A059669).

Crossrefs

Programs

  • Magma
    [p: p in PrimesUpTo(400) | forall{x: x in ResidueClassRing(p) | x^24 ne 2}]; // Bruno Berselli, Sep 14 2012
  • Mathematica
    Select[Prime[Range[PrimePi[400]]], ! MemberQ[PowerMod[Range[#], 24, #], Mod[2, #]] &] (* Bruno Berselli, Sep 14 2012 *)
    ok[p_] := Reduce[Mod[x^24 - 2, p] == 0, x, Integers] == False; Select[Prime[Range[80]], ok] (* Vincenzo Librandi, Sep 20 2012 *)

A059331 Primes p such that x^24 = 2 has no solution mod p, but x^12 = 2 has a solution mod p.

Original entry on oeis.org

113, 281, 353, 593, 617, 1049, 1097, 1193, 1481, 1601, 1753, 1889, 2129, 2273, 2281, 2393, 2689, 3089, 3137, 3761, 3833, 4001, 4153, 4217, 4289, 4457, 4657, 4817, 4937, 5113, 5393, 5569, 6521, 6569, 6761, 7481, 7577, 7793, 7817, 7841, 8273, 8369, 8537
Offset: 1

Views

Author

Klaus Brockhaus, Jan 26 2001

Keywords

Crossrefs

Programs

  • Magma
    [p: p in PrimesUpTo(9000) | not exists{x: x in ResidueClassRing(p) | x^24 eq 2} and exists{x: x in ResidueClassRing(p) | x^12 eq 2}]; // Vincenzo Librandi, Sep 21 2012
  • Mathematica
    Select[Prime[Range[PrimePi[1000]]], !MemberQ[PowerMod[Range[#], 24, #], Mod[2, #]] && MemberQ[PowerMod[Range[#], 12, #], Mod[2, #]]&] (* Vincenzo Librandi, Sep 21 2013 *)

A059669 Primes p such that x^48 = 2 has no solution mod p, but x^24 = 2 has a solution mod p.

Original entry on oeis.org

1217, 1553, 1777, 2833, 4049, 4481, 5297, 6449, 6689, 7121, 8081, 8609, 9137, 9281, 9649, 10337, 10433, 11329, 11633, 12241, 13121, 14321, 14753, 15569, 16433, 16673, 18257, 19793, 23057, 25169, 25889, 26177, 26561, 26993, 27281, 28001, 29153, 29201
Offset: 1

Views

Author

Klaus Brockhaus, Feb 04 2001

Keywords

Crossrefs

Programs

  • Magma
    [p: p in PrimesUpTo(30000) | not exists{x: x in ResidueClassRing(p) | x^48 eq 2} and exists{x: x in ResidueClassRing(p) | x^24 eq 2}]; // Vincenzo Librandi, Sep 21 2012
  • Mathematica
    Select[Prime[Range[PrimePi[30000]]], ! MemberQ[PowerMod[Range[#], 48, #], Mod[2, #]] && MemberQ[PowerMod[Range[#], 24, #], Mod[2, #]] &] (* Vincenzo Librandi, Sep 22 2013 *)

Extensions

a(37)-a(38) from Vincenzo Librandi, Sep 21 2012
Showing 1-3 of 3 results.