OFFSET
0,1
EXAMPLE
a(0)=3 because 10*0+3=3 (prime),
a(1)=13 because 10*1+3=13 (prime),
a(3)=3 because 10*3+3=33 (composite)=>3 (prime),
a(78)=83 because 10*78+3=783 (composite) =>83 (prime).
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Zak Seidov, Feb 24 2008
STATUS
approved