OFFSET
1,1
COMMENTS
Or, primes that are concatenation of two 2-digit primes 98>p>q>10.
There are exactly 36 such primes.
MATHEMATICA
Sort[Select[100Last[#]+First[#]&/@Subsets[Prime[Range[5, 25]], {2}], PrimeQ]] (* Harvey P. Dale, Aug 19 2013 *)
PROG
(PARI) is(n)=isprime(n) && isprime(n\100) && isprime(n%100) && n<9768 \\ Charles R Greathouse IV, Jun 08 2015
CROSSREFS
KEYWORD
fini,full,nonn,base,easy
AUTHOR
Zak Seidov, Nov 27 2009
STATUS
approved