Hello all,

I have a quick question that someone might be able to help me understant. This statement says:

Consider the list of odd primes [3,5,7,....]

Prove that if a and b are adjacent odd primes in the lis, then their sum a+b necessarily has 3 prime factors, where these factors need not be distinct.

Example: 3+5=8=2x2x2 (3 repeated factors of 2)

Example: 47+53=100=2x2x5x5 (4 prime factors)

How do I prove this? I also don't understand how it says a+b necessarily have 3 prime factors, but my 2nd example has 4 ????

Any help is appreciated!