OFFSET
1,2
EXAMPLE
a(1)=1 because nonnegative nonprime(1)-2=-2=negative nonprime and nonnegative nonprime(1)+2=2=prime.
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Apr 12 2010
EXTENSIONS
More terms from R. J. Mathar, Apr 16 2010
STATUS
approved