OFFSET
1,1
COMMENTS
The sequence conjecturally infinite. All squares of the sequence are 9, 81, 6561,... and have the form 3^(2^k), k>=1. However, we conjecture that there is only a finite number of them, or, the same, there is only a finite number of primes of the form 3^(2^k) + 2.
LINKS
Peter J. C. Moses, Table of n, a(n) for n = 1..1200
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Sep 25 2013
EXTENSIONS
More terms from Peter J. C. Moses, Sep 25 2013
STATUS
approved