

A108879


Numbers n such that (n1)*n^n+1 is prime.


1




OFFSET

1,1


LINKS

Table of n, a(n) for n=1..6.


EXAMPLE

2 is in the sequence because (21)*2^2+1 = 1*2^2+1 = 4+1 = 5, which is prime.


MATHEMATICA

Select[Range[1000], PrimeQ[(#  1) #^# + 1] &] (* Vincenzo Librandi, Oct 23 2014 *)


PROG

(PARI) isok(n) = isprime((n1)*n^n+1); \\ Michel Marcus, Oct 23 2014
(MAGMA) [n: n in [1..1000] IsPrime((n1)*n^n+1)]; // Vincenzo Librandi, Oct 23 2014


CROSSREFS

Cf. A108318.
Sequence in context: A325791 A188326 A158094 * A341855 A337038 A058006
Adjacent sequences: A108876 A108877 A108878 * A108880 A108881 A108882


KEYWORD

hard,more,nonn


AUTHOR

Ray G. Opao, Jul 14 2005


STATUS

approved



