VOOZH about

URL: https://oeis.org/A309140

⇱ A309140 - OEIS

login
A309140
Numbers k such that k^(k + 1) + k - 1 is prime.
1
3, 5, 6, 9, 15, 87, 2323, 13733
OFFSET
1,1
COMMENTS
a(7) > 2000.
a(8) > 5000. - Daniel Suteu, Jul 25 2019
a(8) > 10000. - Michael S. Branicky, Apr 01 2023
PROG
(PARI) for(n=1, 100, my(x=n^(n+1)+n-1); if(isprime(x), print1(n, ", ")))
CROSSREFS
Sequence in context: A070117 A176345 A101139 * A102606 A102372 A095829
KEYWORD
nonn,more,hard
AUTHOR
Hugo Pfoertner, Jul 23 2019
EXTENSIONS
a(7) from Daniel Suteu, Jul 25 2019
a(8) from Michael S. Branicky, Nov 04 2024
STATUS
approved