OFFSET
1,3
COMMENTS
a(19) > 10^5. - Michael S. Branicky, Jul 25 2024
PROG
(PARI) is(n)=ispseudoprime(3^n+3*n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Sep 04 2010, based on a posting to the Sequence Fans Mailing List by Charles R Greathouse IV, Aug 23 2010
EXTENSIONS
More terms from Charles R Greathouse IV, Sep 07 2010
STATUS
approved