Prime Numbers

[Pradeep1210]

What I'm getting at is just removing the even numbers from the start hence, only finding the odd numbers. This is because 2 can divide into any even number.

That's exactly what it does. Since 2 is the smallest number, it eliminates all multiples of 2 (i.e. all even numbers) in the first loop. Then continues with 3 then 5 then 7 and so on.

The only difference between the two algorithms that make a performance difference is that while in SieveOfEratosthenes a number can come for elimination more than once, in EulersSieve any number can come for elimination only once.