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 1-2 of 2 results.

A182300 Gaussian-Mersenne primes: primes of the form ((1+i)^p - 1)((1-i)^p - 1).

Original entry on oeis.org

5, 13, 41, 113, 2113, 525313, 536903681, 140737471578113, 9444732965601851473921, 604462909806215075725313, 10384593717069655112945804582584321, 2854495385411919762116496381035264358442074113
Offset: 1

Views

Author

Arkadiusz Wesolowski, Apr 23 2012

Keywords

Comments

See A057429 for the values of p.
Primes of the form q = 2^p +- 2^((p+1)/2) + 1. Note that q == 1 (mod p). - Thomas Ordowski, Apr 18 2019

References

  • John Brillhart et al., Factorizations of b^n +/- 1, b=2,3,5,6,7,10,12 up to high powers, Amer. Math. Soc., Providence RI, 1988, pp. xcvi+236.
  • R. K. Guy, Unsolved Problems in Number Theory, New York: Springer-Verlag, 1994, pp. 33-36.
  • Miriam Hausmann and Harold N. Shapiro, Perfect Ideals over the Gaussian Integers, Comm. Pure Appl. Math. 29 (1976), pp. 323-341.

Crossrefs

Programs

  • Mathematica
    lst = {}; Do[a = (1 + I)^n - 1; b = a*Conjugate[a]; If[PrimeQ[b], AppendTo[lst, b]], {n, 151}]; lst
    gmp[n_]:=Module[{x=(1+I)^n-1},x*Conjugate[x]]; Select[Table[gmp[n],{n,200}],PrimeQ] (* Harvey P. Dale, Apr 27 2016 *)

A207040 Generalized Gaussian-Mersenne primes (see below).

Original entry on oeis.org

5, 13, 29, 37, 41, 61, 109, 113, 397, 1321, 1429, 1613, 2113, 14449, 26317, 246241, 279073, 312709, 525313, 4327489, 7416361, 29247661, 47392381, 107367629, 536903681, 1326700741, 40388473189, 118750098349, 275415303169, 415878438361, 1759217765581
Offset: 1

Views

Author

Arkadiusz Wesolowski, May 07 2012

Keywords

Crossrefs

Supersequence of A182300 (Gaussian-Mersenne primes). Cf. A088962, A057429.

Programs

  • Mathematica
    lst = {}; Do[s = Numerator@FullSimplify@Exp[2*Re@Log@Cyclotomic[n, (1 + I)/2]]; If[PrimeQ[s] && ! MemberQ[lst, s], AppendTo[lst, s]], {n, 2^7}]; Take[Sort[lst], 31]

Formula

The numerator of the rational expression exp(2*Re(log(Phi_n((1 + i)/2)))) is prime, where Phi_n is the n-th cyclotomic polynomial. See A088962 for the values of n that generate primes.
Showing 1-2 of 2 results.