OFFSET
1,1
COMMENTS
EXAMPLE
124 and 421 are in the sequence because 124=4*31 and both numbers
31=(10^2-7)/3 and 421=(127*10^(2-1)-7)/3 are primes. It seems that
there is no further term.
CROSSREFS
KEYWORD
nonn
AUTHOR
Farideh Firoozbakht, Jan 22 2005
STATUS
approved