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.

Previous Showing 11-15 of 15 results.

A309533 Numbers k such that (144^k + 1)/145 is prime.

Original entry on oeis.org

23, 41, 317, 3371, 45259, 119671
Offset: 1

Views

Author

Paul Bourdelais, Aug 06 2019

Keywords

Comments

The corresponding primes are terms of A059055. - Bernard Schott, Aug 09 2019

Crossrefs

Programs

  • Mathematica
    Do[p=Prime[n]; If[PrimeQ[(144^p + 1)/145], Print[p]], {n, 1, 1000000}]
  • PARI
    is(n)=ispseudoprime((144^n+1)/145)

A236167 Numbers k such that (47^k + 1)/48 is prime.

Original entry on oeis.org

5, 19, 23, 79, 1783, 7681
Offset: 1

Views

Author

Robert Price, Jan 19 2014

Keywords

Comments

a(7) > 10^5.

Crossrefs

Programs

  • Mathematica
    Do[ p=Prime[n]; If[ PrimeQ[ (47^p + 1)/48 ], Print[p] ], {n, 1, 9592} ]
  • PARI
    is(n)=ispseudoprime((47^n+1)/48) \\ Charles R Greathouse IV, Jun 06 2017
    
  • Python
    from sympy import isprime
    def afind(startat=0, limit=10**9):
      pow47 = 47**startat
      for k in range(startat, limit+1):
        q, r = divmod(pow47+1, 48)
        if r == 0 and isprime(q): print(k, end=", ")
        pow47 *= 47
    afind(limit=300) # Michael S. Branicky, May 19 2021

A185230 Numbers n such that (33^n + 1)/34 is prime.

Original entry on oeis.org

5, 67, 157, 12211, 313553
Offset: 1

Views

Author

Robert Price, Aug 29 2013

Keywords

Comments

All terms are prime.
a(5) > 10^5.

Crossrefs

Programs

  • Mathematica
    Do[ p=Prime[n]; If[ PrimeQ[ (33^p + 1)/34 ], Print[p] ], {n, 1, 9592} ]
  • PARI
    is(n)=ispseudoprime((33^n+1)/34) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(5) from Paul Bourdelais, Feb 26 2021

A236530 Numbers n such that (48^n + 1)/49 is prime.

Original entry on oeis.org

5, 17, 131, 84589
Offset: 1

Views

Author

Robert Price, Jan 27 2014

Keywords

Comments

All terms are primes.
a(5) > 10^5.

Crossrefs

Programs

  • Mathematica
    Do[ p=Prime[n]; If[ PrimeQ[ (48^p + 1)/49 ], Print[p] ], {n, 1, 9592} ]
  • PARI
    is(n)=ispseudoprime((48^n+1)/49) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

Incorrect first term deleted by Robert Price, Feb 21 2014

A338525 Numbers k such that (11^k + 6^k)/17 is prime.

Original entry on oeis.org

5, 7, 107, 383, 17359, 21929, 26393
Offset: 1

Views

Author

Tim Johannes Ohrtmann, Nov 01 2020

Keywords

Comments

All terms are prime.
The corresponding primes are 9931, 1162771, ...

Crossrefs

Programs

  • Magma
    [n: n in [1..10000] |IsPrime((11^n + 6^n)/17)]
  • Mathematica
    Select[Range[1, 10000], PrimeQ[(11^# + 6^#)/17] &]
  • PARI
    for(n=1, 10000, if(isprime((11^n + 6^n)/17), print1(n, ", ")))
    
Previous Showing 11-15 of 15 results.