Definitions
In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes.



Task
Write a program to determine (and show here) all additive primes less than 500.

Optionally, show the number of additive primes.



Also see

   the OEIS entry:   A046704 additive primes.
   the prime-numbers entry:   additive primes.
   the geeks for geeks entry: additive prime number.
   the prime-numbers fandom: additive primes.


using Primes
 
let
    p = primesmask(500)
    println("Additive primes under 500:")
    pcount = 0
    for i in 2:499
        if p[i] && p[sum(digits(i))]
            pcount += 1
            print(lpad(i, 4), pcount % 20 == 0 ? "\n" : "")
        end
    end
    println("\n\n$pcount additive primes found.")
end
 