

A191568


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


1




OFFSET

1,2


COMMENTS

The corresponding primes are a subset of the generalized Cullen primes (A210339 united with A050920).  Jeppe Stig Nielsen, Apr 12 2016


LINKS

Table of n, a(n) for n=1..8.


EXAMPLE

a(1)=1 because 1*2^1+1=3 is prime, a(2)=2 because 2*3^2+1=19 is prime, a(3)=3 because 3*4^3+1=193 is prime, a(4)=9 because 9*10^9+1=9000000001 is prime, a(5)=10 because 10*11^10+1=259374246011 is prime.


MATHEMATICA

Select[Range@ 100, PrimeQ[# (# + 1)^# + 1] &] (* Michael De Vlieger, Apr 12 2016 *)


PROG

(PARI) is(n)=ispseudoprime(n*(n+1)^n+1) \\ Charles R Greathouse IV, Jun 13 2017


CROSSREFS

Cf. A109618, A110709, A210339, A271718.
Sequence in context: A257026 A057291 A135107 * A279549 A030743 A098020
Adjacent sequences: A191565 A191566 A191567 * A191569 A191570 A191571


KEYWORD

nonn,hard,more


AUTHOR

JuriStepan Gerasimov, Jun 13 2011


STATUS

approved



