login
A216421
Numbers k such that 13^k + k^13 + 1 is prime.
1
0, 9, 4371, 7985, 14711
OFFSET
1,2
COMMENTS
a(6) > 10^5. - Robert Price, Feb 23 2014
MATHEMATICA
Select[Range[0, 5000], PrimeQ[13^# + #^13 + 1] &]
PROG
(PARI) is(n)=ispseudoprime(13^n+n^13+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Vincenzo Librandi, Sep 07 2012
EXTENSIONS
a(4)-a(5) from Robert Price, Feb 23 2014
STATUS
approved