A093522 Numbers k such that k^k - (k-1)^2 is prime.

2, 3, 5, 21, 75

Offset

1,1

Comments

a(6), if it exists, is greater than 9000. - Ryan Propper, May 17 2006

a(6), if it exists, is greater than 20000. - Michael S. Branicky, Aug 11 2024

Links

Table of n, a(n) for n=1..5.

Mathematica

Select[Range[80], PrimeQ[#^#-(#-1)^2]&] (* Harvey P. Dale, Aug 15 2013 *)

Prog

(PARI) is(n)=ispseudoprime(n^n-(n-1)^2) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A259376 A060321 A351989 * A352124 A093499 A339228

Adjacent sequences: A093519 A093520 A093521 * A093523 A093524 A093525

Keyword

more,nonn

Author

Jason Earls, May 23 2004

Status

approved