OFFSET
1,2
COMMENTS
The associated primes are 3, 11, 43, 467, 354251,....
EXAMPLE
a(1)=1 because 2*(3^1-2*1)+1=3 is a prime, a(2)=2 because 2*(3^2-2*2)+1=11 is a prime, a(3)=3 because 2*(3^3-2*3)+1=43 is a prime, a(4)=5 because 2*(3^5-2*5)+1=467 is a prime, a(5)=11 because 2*(3^11-2*11)+1=354251 is a prime.
PROG
(PARI) is(n)=ispseudoprime(2*(3^n-2*n)+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Juri-Stepan Gerasimov, Sep 24 2011
EXTENSIONS
a(9)-a(16) from Michael S. Branicky, Jul 15 2023
a(17) from Michael S. Branicky, Aug 25 2024
STATUS
approved