A191513 Numbers n such that n*(n-1)^n-1 is prime.

3, 5, 10, 11, 18, 127, 286, 560, 1025

Offset

1,1

Links

Table of n, a(n) for n=1..9.

Example

a(1)=3 because 3*2^3-1=23 is prime, a(2)=5 because 5*4^5-1=5119 is prime, a(3)=10 because 10*9^10-1=34867844009 is prime, a(4)=11 because 11*10^11-1=1099999999999 is prime.

Maple

isA191513 := proc(n) n*(n-1)^n-1 ; isprime(%) ; end proc:
for n from 1 do if isA191513(n) then print(n); end if; end do: # R. J. Mathar, Jun 30 2011

Prog

(Magma) [n: n in [1..600]| IsPrime(n*(n-1)^n-1)]; // Vincenzo Librandi, Jun 13 2011
(PARI) for(n=1, 1e4, if(ispseudoprime(n*(n-1)^n-1), print1(n", "))) \\ Charles R Greathouse IV, Jun 14 2011

Crossrefs

Cf. A191699, A191717.

Sequence in context: A332049 A113858 A101130 * A254540 A326419 A102309

Adjacent sequences: A191510 A191511 A191512 * A191514 A191515 A191516

Keyword

nonn

Author

Juri-Stepan Gerasimov, Jun 13 2011

Extensions

Corrected and extended by Vincenzo Librandi and Charles R Greathouse IV, Jun 14 2011

Status

approved