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.

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A229612 Numbers n such that (19^n + 5^n)/24 is prime.

Original entry on oeis.org

11, 37, 107, 181, 449, 457, 3583, 9133, 10139, 99689
Offset: 1

Views

Author

Robert Price, Sep 26 2013

Keywords

Comments

All terms are primes.
a(11) > 10^5.

Crossrefs

Cf. A128075, A228130, A225818.

Programs

  • Mathematica
    k=19; Do[p=Prime[n]; f=(k^p+5^p)/(k+5); If[ PrimeQ[f], Print[p] ], {n, 1, 9592}]
  • PARI
    is(n)=ispseudoprime((19^n+5^n)/24) \\ Charles R Greathouse IV, Jun 13 2017

A231329 Numbers n such that (19^n + 4^n)/23 is prime.

Original entry on oeis.org

7, 11, 211, 14461
Offset: 1

Views

Author

Robert Price, Nov 07 2013

Keywords

Comments

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

Crossrefs

Cf. A227049, A228558, A128075, A229612.

Programs

  • Mathematica
    Select[ Prime[ Range[1, 100000] ], PrimeQ[ (19^# + 4^#)/23 ]& ]
  • PARI
    is(n)=ispseudoprime((19^n+4^n)/23) \\ Charles R Greathouse IV, Jun 13 2017
Previous Showing 11-12 of 12 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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