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.

A059801 Numbers k such that 4^k - 3^k is prime.

Original entry on oeis.org

2, 3, 7, 17, 59, 283, 311, 383, 499, 521, 541, 599, 1193, 1993, 2671, 7547, 24019, 46301, 48121, 68597, 91283, 131497, 148663, 184463, 341233
Offset: 1

Views

Author

Mike Oakes, Feb 23 2001

Keywords

Comments

Some of the larger entries may only correspond to probable primes.
The values corresponding to 1193 (719 digits) and 1993 (1200 digits) have been certified prime with Primo. - Rick L. Shepherd, Sep 10 2002
8 more terms found by Jean-Louis Charton during 2004 - 2006. Corresponding numbers of decimal digits are 14461, 27876, 28972, 41300, 54958, 79170, 89505, 111058, 205443. - Alexander Adamchuk, Dec 02 2006

Crossrefs

Programs

A129736 Primes of the form 4^k - 3^k.

Original entry on oeis.org

7, 37, 14197, 17050729021, 332306984815842876487217260305275077
Offset: 1

Views

Author

N. J. A. Sloane, May 13 2007

Keywords

Crossrefs

Programs

  • GAP
    Filtered(List([1..100], n -> 4^n-3^n), IsPrime); # Muniru A Asiru, Feb 09 2018
    
  • Magma
    [a: n in [0..300] | IsPrime(a) where a is 4^n-3^n]; // Vincenzo Librandi, Nov 23 2010
    
  • Maple
    select(isprime, [seq(4^n - 3^n, n=0..100)]); # Muniru A Asiru, Feb 09 2018
  • Mathematica
    fQ[n_] := If[PrimeQ[4^n - 3^n], 4^n - 3^n, Nothing]; Array[fQ, 300] (* Robert G. Wilson v, Feb 12 2018 *)
  • PARI
    lista(nn) = for(k=1, nn, if(isprime(p=4^k-3^k), print1(p", "))) \\ Altug Alkan, Mar 03 2018

Formula

a(n) = A005061(A059801(n)). - Michel Marcus, Feb 12 2018
Showing 1-2 of 2 results.