OFFSET
1,1
EXAMPLE
a(3) = 773 because 773 is the largest 3-digit prime that is a concatenation of a 1-digit prime and a 2-digit prime that is itself a concatenation of 1-digit primes.
CROSSREFS
KEYWORD
nonn,base,new
AUTHOR
Karl W. Heuer, Sep 22 2024
STATUS
approved