OFFSET
1,1
COMMENTS
All terms are prime.
a(7) > 10^5. - Robert Price, Aug 26 2013
PROG
(PARI) is(n)=ispseudoprime((16^n+15^n)/31) \\ Charles R Greathouse IV, May 22 2017
CROSSREFS
KEYWORD
hard,nonn,more
AUTHOR
Jean-Louis Charton, Jul 03 2013
STATUS
approved