# prime number finder.

• 03-05-2004
Aalmaron
prime number finder.
well the other day i noticed that the diferance between 2 perfect squares is a prime number, so i made a program that does the math for you.

Code:

```#include<iostream> using namespace std; int counter = 1; int main() { int num1;   do   {     cout << "enter a number: ";     cin >> num1;     int num2 =  num1 + 1;     int square1 = num1 * num1;     int square2 = num2 * num2;     int prime = square2 - square1;     cout << "your prime number is: " << prime << endl;         }   while (counter = 1);   cin.get();   return 0; }```
yeah i couldnt get a "yes/no would you like to do it again" thing to work, so i just made it loop like that.

also, dont try to enter a letter, it spazzes out. :confused:
• 03-05-2004
joshdick
5^2 = 25
4^2 = 16

25 - 16 = 9, which is not a prime.

I regret to inform you that your theorem doesn't hold, but I genuinely applaud your interest in number theory. I suggest getting a book on the subject or taking a course in it. It's good stuff.
• 03-05-2004
Aalmaron
damnit, i just came to inform you of that, heh. :p

i've been testing it all morning and just decided to work with the small numbers, damn small numbers make me feal stupid :( lol:D

i tested up to getting the answer 65. here are my results. number i put in)number i got(numbers its devisible by
4)9(3
7)15(3,5
10)21(7
12)25(5
17)35(5,7
22)45(5,9-15,3
24)49(7
27)55(5,11
32)65(5,13

it seems that its almost true, except for being devisible by the prime numbers themselves, and - in the of 22, a number previouly gotten.

i still have work. thanks for wasting your time to read that ;)