A110709 Nonprimes of the form n*(n-1)^n - 1.
1, 323, 93749, 1959551, 46118407, 1207959551, 37661140520651, 1390911669927935, 55123269399790045, 2333521433367183359, 105094533691406249999, 5017514388048998039551, 13456471561751415850795007, 751799469150919163867112019
Offset: 1
Keywords
Examples
a(1) = 1 = 2*1^2 - 1. a(2) = 323 = 4*3^4 - 1.
Links
- Vincenzo Librandi, Table of n, a(n) for n = 1..100
Programs
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Magma
[a: n in [2..40] | not IsPrime(a) where a is n*(n-1)^n-1]; // Vincenzo Librandi, Jun 13 2011
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Mathematica
Select[Table[n (n - 1)^n - 1, {n, 2, 20}], ! PrimeQ[#] &] (* Vincenzo Librandi, Mar 22 2014 *)
Extensions
Corrected and extended by Vincenzo Librandi, Jun 13 2011
Comments