

A058912


Numbers n such that n^n + n  1 is prime.


4




OFFSET

1,1


COMMENTS

Except for the first term all terms are of the form 3k or 3k+1. There is no further term up to 2300.  Farideh Firoozbakht, Oct 18 2006
Corresponding values of primes are in A187605.  Jaroslav Krizek, Nov 14 2013


LINKS

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


EXAMPLE

a(2)=3 because 3^3+(31)=29.


MATHEMATICA

Do[ If[ PrimeQ[ n^n + n  1], Print[n]], {n, 1, 750} ]


PROG

(PARI) is(n)=ispseudoprime(n^n+n1) \\ Charles R Greathouse IV, Feb 20 2017


CROSSREFS

Cf. A058911 (n^n+1+1).
Sequence in context: A140555 A196446 A265799 * A040145 A142955 A213896
Adjacent sequences: A058909 A058910 A058911 * A058913 A058914 A058915


KEYWORD

nonn


AUTHOR

Felice Russo, Jan 10 2001


EXTENSIONS

One more term from Farideh Firoozbakht, Oct 18 2006


STATUS

approved



