Jel zna neko da resi ili da bar ponudi ideju ili malo da me usmeri po sledecem pitanju; naime treba da dokazem (ili opovrgnem) da se svaki prirodan broj moze predstaviti kao zbir 3 PROSTA broja !
Da li postoji nacin da se odredi naredni prost broj u nizu prirodnih brojeva ? I jos nesto : kako matematicki da dokazem da se svaki prost broj moze predstaviti kao 6n-1 ili 6n+1 ?
Perhaps the most rediscovered result about primes numbers is the following:
I found that every prime number over 3 lies next to a number divisible by six. Using Matlab with the help of a friend, we wrote a program to test this theory and found that at least within the first 1,000,000 primes this holds true.
Checking a million primes is certainly energetic, but it is not necessary (and just looking at examples can be misleading in mathematics). Here is how to prove your observation: take any integer n greater than 3, and divide it by 6. That is, write
n = 6q + r
where q is a non-negative integer and the remainder r is one of 0, 1, 2, 3, 4, or 5.
If the remainder is 0, 2 or 4, then the number n is divisible by 2, and can not be prime.
If the remainder is 3, then the number n is divisible by 3, and can not be prime.
So if n is prime, then the remainder r is either
1 (and n = 6q + 1 is one more than a multiple of six), or
5 (and n = 6q + 5 = 6(q+1) - 1 is one less than a multiple of six).
Remember that being one more or less than a multiple of six does not make a number prime. We have only shown that all primes other than 2 and 3 (which divides 6) have this form.
...jer tako smo u mogućnosti.