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.

A222265 Numbers n such that (13^n + 2^n)/15 is prime.

Original entry on oeis.org

7, 31, 103, 223, 503, 1171, 1973, 4111, 4729
Offset: 1

Views

Author

Robert Price, May 05 2013

Keywords

Comments

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

Crossrefs

Programs

  • Mathematica
    Select[Prime[Range[1, 100000]], PrimeQ[(13^# + 2^#)/15]&]
  • PARI
    forprime(p=3,10^6, if(ispseudoprime((13^p + 2^p)/15), print1(p,", ") ) ); \\ Joerg Arndt, Jul 29 2013

Extensions

Removed incorrect first term of "2".

A227049 Numbers k such that (15^k + 4^k)/19 is prime.

Original entry on oeis.org

3, 31, 157, 239, 1553, 5521, 25561
Offset: 1

Views

Author

Robert Price, Jun 29 2013

Keywords

Comments

All terms are primes.
a(8) > 10^5.

Crossrefs

Programs

  • Mathematica
    Select[ Prime[ Range[1, 100000] ], PrimeQ[ (15^# + 4^#)/19 ]& ]
  • PARI
    is(n)=ispseudoprime((15^n+4^n)/19) \\ Charles R Greathouse IV, Jun 06 2017
Showing 1-2 of 2 results.