Ok, going to give another go … I think I can use the prime checker to start at the high end and work my way down. It will probably take longer but I won’t have try to size an array and track prime factors.
Include some stuff, maybe some libraries? Num, Current, Result Create our starting point by dividing our Num by 2 (or something, maybe us a sieve?) Loop from previous result to 0 Test for prime If Prime divide Num If no reminder Print number