Re: [PrimeNumbers] Primality Testing
- At 06:50 PM 9/6/2004, Ronald Dwyer wrote:
3. Of the numbers that end in the digit 9, one thing we can do is
>this: if we 'cast out' that 9, and if the remaing digits are aThat is of very little help because it tells if the number is divisible by
>multiple of 3, then, the original number, N, is a composite. For
>example, the following numbers are composite: 1239, 3339, 50109.
3, so that rules out very few of the cases.