OFFSET
1,2
COMMENTS
EXAMPLE
a(1)=1 because 2^1-3=-1 is nonprime and 2^1+3=5 is prime.
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Mar 14 2010
EXTENSIONS
Corrected by Charles R Greathouse IV, Mar 20 2010
STATUS
approved