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.

A308413 Numbers k such that 23^(k+19) + 19^(k+17) + 17^(k+13) + 13^(k+11) + 11^(k+7) + 7^(k+5) + 5^(k+3) + 3^(k+2) - 1 is prime.

Original entry on oeis.org

6, 60, 66, 414, 29340
Offset: 1

Views

Author

Mikk Heidemaa, May 31 2019

Keywords

Comments

a(6) > 50000 (if it exists).

Crossrefs

Cf. A306573.

Programs

  • Mathematica
    ParallelTable[If[PrimeQ[23^(n+19) + 19^(n+17) + 17^(n+13) + 13^(n+11) + 11^(n+7) + 7^(n+5) + 5^(n+3) + 3^(n+2) - 1], n, Nothing], {n, 30000}]

A308553 Numbers k such that 5^(k+3) + 3^(k+2) + 2^(k+1) + 1 is prime.

Original entry on oeis.org

0, 4, 8, 524, 972, 3780, 7704
Offset: 1

Views

Author

Mikk Heidemaa, Jun 07 2019

Keywords

Comments

Larger k values yield probable primes.
a(8) > 100000 (if it exists). - Michael S. Branicky, Nov 11 2024

Crossrefs

Cf. A306573.

Programs

  • Mathematica
    ParallelTable[If[PrimeQ[5^(n+3) + 3^(n+2) + 2^(n+1) + 1], n, Nothing], {n, 0, 10^4}]
Showing 1-2 of 2 results.

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

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