Given that no one has yet found a solution to that problem, I don't think there would be an easy inductive solution.
So there doesnt exist any method used in Discrete Math to prove this yet, right ?
It cant be done by looking on it as operation '+' upon numeral system(or group) which contains all prime numbers Pn {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, ...}; Pn^2 -> E ?
where E is natural system(group) of natural even numbers (2k) higher than 2.