

A255730


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


0




OFFSET

1,2


COMMENTS

a(6) corresponds to a prime having 153 digits.
If it exists, a(7) > 5000.
n does not have the form 20k+2 (which leads to a multiple of 5) or 42k+26 (which leads to a multiple of 7).


LINKS



EXAMPLE

4 is in the sequence because 4^4  3^4 + 4 = 179 is prime.


MATHEMATICA

Select[Range[1000], PrimeQ[#^#  (#  1)^# + #] &]


PROG

(Magma) [n: n in [0..500] IsPrime(n^n  (n1)^n + n)];


CROSSREFS



KEYWORD

nonn,more


AUTHOR



STATUS

approved



