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A098463 Numbers k such that A055869(k) = (k+1)^k - k^k is prime. 3
2, 3, 5, 7, 167 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The next term is > 5000.

LINKS

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

EXAMPLE

a(2) = 3 because (3+1)^3 - 3^3 = 4^3 - 3^3 = 64 - 27 = 37 is prime.

MATHEMATICA

Select[Range[300], PrimeQ[(#+1)^#-#^#]&] (* Vladimir Joseph Stephan Orlovsky, Mar 03 2011*)

PROG

(MAGMA) [n: n in [0..190]| IsPrime((n+1)^n -n^n)]; // Vincenzo Librandi, Jun 22 2014

(PARI) isok(k) = ispseudoprime((k+1)^k - k^k); \\ Jinyuan Wang, Mar 19 2020

CROSSREFS

Cf. A055869 ((n+1)^n-n^n), A085682 (k^k-(k-1)^k is prime).

Sequence in context: A075048 A281021 A230046 * A064155 A230047 A230042

Adjacent sequences:  A098460 A098461 A098462 * A098464 A098465 A098466

KEYWORD

nonn,hard,more

AUTHOR

Hugo Pfoertner, Sep 14 2004

STATUS

approved

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Last modified November 30 08:19 EST 2021. Contains 349419 sequences. (Running on oeis4.)