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.

A063939 Numbers p from A001125 such that 2*p-3 is prime.

Original entry on oeis.org

41, 251, 991, 1471, 2551, 3301, 4211, 4721, 4931, 5167, 5581, 5791, 7351, 8317, 8581, 9157, 9781, 11701, 12517, 13093, 15541, 16741, 16927, 17341, 18301, 18397, 19121, 19231, 20411, 22571, 23911, 24151, 25741, 26293, 26317, 26681, 27031
Offset: 1

Views

Author

Jason Earls, Aug 31 2001

Keywords

Crossrefs

Cf. A001125.

Programs

  • PARI
    j=[]; forprime(p=3,40000, if(znprimroot(p)==6, if(isprime(2*p- 3),j=concat(j,p)))); j
    
  • PARI
    { n=0; p=0; for (m=1, 10^9, p=nextprime(p+1); if (znprimroot(p)==6 && isprime(2*p - 3), write("b063939.txt", n++, " ", p); if (n==1000, break)) ) } \\ Harry J. Smith, Sep 03 2009

A001124 Primes with 5 as smallest primitive root.

Original entry on oeis.org

23, 47, 73, 97, 103, 157, 167, 193, 263, 277, 307, 383, 397, 433, 503, 577, 647, 673, 683, 727, 743, 863, 887, 937, 967, 983, 1033, 1093, 1103, 1153, 1163, 1223, 1367, 1487, 1543, 1583, 1607, 1777, 1823, 1847, 1933, 1993, 2003, 2017, 2063, 2087, 2113, 2203, 2207
Offset: 1

Views

Author

Keywords

References

  • M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 864.
  • M. Kraitchik, Recherches sur la Théorie des Nombres. Gauthiers-Villars, Paris, Vol. 1, 1924, Vol. 2, 1929, see Vol. 1, p. 57.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A001122, A001123, A001125, etc.

Programs

  • Mathematica
    << NumberTheory`NumberTheoryFunctions`; Prime[ Select[ Range[200], PrimitiveRoot[ Prime[ # ] ] == 5 & ] ]
    (* first load *) << NumberTheory`NumberTheoryFunctions` (* then *) Select[ Prime@Range@300, PrimitiveRoot@# == 5 &] (* Robert G. Wilson v, May 11 2001 *)
    Select[Prime[Range[350]],PrimitiveRoot[#]==5&] (* The PrimitiveRoot function is now part of Mathematica's core, so no add-in needs to be loaded before calling it *) (* Harvey P. Dale, Dec 06 2014 *)
  • Python
    from itertools import islice
    from sympy import nextprime, primitive_root
    def A001124_gen(): # generator of terms
        p = 5
        while (p:=nextprime(p)):
            if primitive_root(p)==5:
                yield p
    A001124_list = list(islice(A001124_gen(),30)) # Chai Wah Wu, Feb 13 2023

Extensions

More terms from Robert G. Wilson v, May 10 2001

A072190 Indices of primes with primitive root 2.

Original entry on oeis.org

2, 3, 5, 6, 8, 10, 12, 16, 17, 18, 19, 23, 26, 28, 32, 34, 35, 38, 40, 41, 42, 45, 47, 49, 57, 62, 66, 69, 70, 74, 75, 77, 81, 82, 86, 89, 91, 94, 97, 99, 100, 101, 102, 103, 107, 112, 114, 119, 120, 121, 123, 126, 127, 134, 137, 138, 139, 142, 144, 145, 147
Offset: 1

Views

Author

Miklos Kristof, Jul 02 2002

Keywords

Comments

Artin conjectured that this sequence is infinite (this is the famous Artin Conjecture).

Examples

			8 is an element of the sequence: 19 the 8th prime and 2 is primitive root of 19. 9 is not element of the sequence, since 23 is the 9th prime and 2 is not primitive root of 23.
		

References

  • M. Abramowitz and I.A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 864
  • J. H. Conway and R. K. Guy, The Book of Numbers, Copernicus Press, New York, 1996. see p. 169
  • L. Huber, manuscripts on Group Theory and Number Theory, 1990-1995

Crossrefs

Programs

  • Mathematica
    Select[Range[300], MultiplicativeOrder[2, Prime[#]] == Prime[#] - 1 &] (* T. D. Noe, Apr 16 2014 *)

Extensions

Edited by N. J. A. Sloane, Apr 11 2009
Extended by T. D. Noe, Apr 16 2014
Showing 1-3 of 3 results.