OFFSET
1,1
COMMENTS
EXAMPLE
n=16, swap 1 and 6 to get 61 prime
n=121, swap 1 and 2 to get 211 prime
n=169, swap 1 and 6 to get 619 prime.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Zak Seidov, Dec 12 2009
STATUS
approved