4 ms·

Counter example x = 3 y = 5 2*(2*3*5+3+5)+1 2*38+1 77

• zeepickler 14y ago
  Yes, this an example of an odd composite. As I said 2xy + x + y creates odd composites (numbers that are odd and not prime). I'm not saying this is prime. I was saying that the other patterns below are prime. However, since I posted this, I found a flaw with the 7 +6n +1 and 7+ 6n + 2 pattern. However, the 5,5+6,5+6+7, etc pattern holds up for up to the numbers I checked. I still have further investigation to do...