## Is there any set of numbers that, when muliplied with anything from \mathbb{N}$, results in an uneven number?

I noticed the (very easy to see) fact that, whenever you multiply any natural number $n$ with anything having a prime factor of $2$, you get an even number. For example: $ 3 \times 2 = 6$, even $5 \times 6 = 30 $, even and so on. It’s easy to see that this is … Read more