Question: sum of 2 odd number is prime?
Answer: To make the sum of two numbers odd, one of the numbers must be odd and the other even. There is only one even prime, so that limits you to sums of the form 2+p. Thus the odd numbers that are the sum of two primes are exactly the ones that are two more than a prime. The first few are 5,7,9,13,15,19,21,25,31,33,39,43…