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.

A187605 Primes of the form k^k + k - 1.

Original entry on oeis.org

5, 29, 1978419655660313589123997, 205891132094649000000000000000000000000000029
Offset: 1

Views

Author

Marco Ripà, Mar 11 2011

Keywords

Comments

See A058912 for numbers k such that k^k + k - 1 is prime. Subsequence of A231712 (numbers n^n + n - 1). - Jaroslav Krizek, Nov 13 2013
The next prime has 1460 digits. - Jinyuan Wang, Mar 01 2020

Links

Crossrefs

Cf. A058912, A231712, A268987.

Programs

  • Mathematica
    Do[p=n^n+n-1; If[PrimeQ[p], Print[p]], {n, 100}]
  • PARI
    lista(nn) = for(k=1, nn, if(ispseudoprime(q=k^k+k-1), print1(q, ", "))); \\ Jinyuan Wang, Mar 01 2020

A309140 Numbers k such that k^(k + 1) + k - 1 is prime.

Original entry on oeis.org

3, 5, 6, 9, 15, 87, 2323, 13733
Offset: 1

Views

Author

Hugo Pfoertner, Jul 23 2019

Keywords

Comments

a(7) > 2000.
a(8) > 5000. - Daniel Suteu, Jul 25 2019
a(8) > 10000. - Michael S. Branicky, Apr 01 2023

Crossrefs

Cf. A155499, A268987.

Programs

  • PARI
    for(n=1,100,my(x=n^(n+1)+n-1);if(isprime(x),print1(n,", ")))

Extensions

a(7) from Daniel Suteu, Jul 25 2019
a(8) from Michael S. Branicky, Nov 04 2024
Showing 1-2 of 2 results.

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

Content is available under The OEIS End-User License Agreement.