Goldbach's strong conjecture states that every even integer greater than 2 can be expressed as the sum of two primes. For example: 4 = 2+2, 6 = 3+3, 8 = 3+5, 10 = 3+7 = 5+5, 12 = 5+7 etc.
As a corrollary, Goldbach's weak conjecture states that every odd integer greater than 7 can be expressed as the sum of three odd primes. For example: 9 = 3+3+3, 11 = 3+3+5, 13 = 3+3+7 = 3+5+5, 15 = 3+5+7 = 5+5+5 etc.
A third conjecture was written by Goldbach in the margin of a letter, and (in its modern version) states that
" Every integer greater than 5 can be expressed as the sum of three primes. "
Your task is to write a function which takes a positive integer n as input, and which returns a 1-by-3 vector y, which contains three numbers that are primes and whose sum equals n. If there exist multiple solutions for y, then any one of those solutions will suffice. However, y must be in sorted order. You can assume that n will be an integer greater than 5.