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A108318 Numbers n such that (n+1)*n^n-1 is prime. 3
2, 3, 4, 5, 7, 11, 15, 26, 52, 116, 359, 1547, 2465 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
15 is in the sequence because (15+1)*15^15-1 = 16*15^15-1 = 7006302246093749999, which is prime.
MATHEMATICA
Select[Range[1000], PrimeQ[(# + 1) #^# - 1] &] (* Vincenzo Librandi, Oct 23 2014 *)
PROG
(PARI) isok(n) = isprime((n+1)*n^n-1); \\ Michel Marcus, Oct 23 2014
(Magma) [n: n in [1..1000] |IsPrime((n+1)*n^n-1)]; // Vincenzo Librandi, Oct 23 2014
CROSSREFS
Cf. A108879.
Sequence in context: A347983 A259466 A046420 * A358876 A006456 A018134
KEYWORD
more,nonn
AUTHOR
Ray G. Opao, Jun 30 2005
STATUS
approved

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Last modified March 28 14:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)