OFFSET
1,2
COMMENTS
For n = 1, 2, 3, 4, 24 the corresponding primes are 29, 1259, 46439, 1678319, 22452257707354557235348829785471057919.
a(22) > 10^5. - Robert Price, Jan 06 2020
EXAMPLE
4 is in the sequence because 36^4 - 6^4 - 1 = 1678319 is prime.
MATHEMATICA
Select[Range[1000], PrimeQ[36^# - 6^# - 1] &]
PROG
(Magma) [n: n in [0..300] | IsPrime(36^n-6^n-1)];
(PARI) for(n=1, 1e3, if(ispseudoprime(36^n - 6^n - 1), print1(n, ", "))) \\ Altug Alkan, Dec 12 2015
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Vincenzo Librandi, Dec 12 2015
EXTENSIONS
a(14)-a(18) from Ray Chandler, Sep 25 2019
a(18) corrected and a(19)-a(21) added by Robert Price, Jan 06 2020
STATUS
approved