/* header files */





#include<iostream>


#include<iomanip>


#include<stdio.h>


#include<conio.h>


#include<cmath>





using namespace std;





/* function prototypes */





void primenumber();


void perfectnumberoutput();





/* variable identifiers */





float prime_factor_check;//variable where value of ((2^n)-1) stored so it can be checked if it is a prime number


__int64 perfect_number = 0;//variable where the computed value of a valid perfect number is stored


int n = 0;//the 'n' value in the expression (pow(2.0,n-1) * (pow(2.0,n)-1))


bool prime = false;//boolean identifier to show if (pow(2.0,n)-1) is a prime number





void main()


{


	cout << "The First Seven Perfect Numbers Are:" << endl << endl << ": ";





	while(perfect_number < 100000000000)


	{


		primenumber();//call function primenumber()


		perfectnumberoutput();//call function perfectnumberoutput()


		n++;//increase 'n' once every program cycle


	}





	cout << endl << endl << "Hit any key to exit. . .";





	while(_kbhit() == 0)


	{//loop until a key is pressed


	}


}





void primenumber()


{


	for(int i = 2;i <= (pow(2.0,n)-1)-1;i++)


	{//'for loop' to divide (pow(2.0,n)-1) by every number greater than 1 and less than itself


		prime_factor_check = (pow(2.0,n)-1) / i;			





		if(!(prime_factor_check > static_cast<int>(prime_factor_check) && prime_factor_check < static_cast<int>(prime_factor_check + 1)))


		{//'if statement' to check for any other factors of (pow(2.0,n)-1) besides 1 and itself making it a non prime number (composite number) and ending the 'for loop'


			prime = false;


			i = (pow(2.0,n)-1);


		}


		else


		{//if there are no other factors of (pow(2.0,n)-1) besides 1 and itself then (pow(2.0,n)-1) is a prime number


			prime = true;


		}


	}


}





void perfectnumberoutput()


{//outputs all of the perfect numbers that were computed


	if(prime == true)


	{


		if(perfect_number < 10000000000)


		{


			perfect_number = (pow(2.0,n-1) * (pow(2.0,n)-1));


			cout << fixed << setprecision(0) << perfect_number;


			cout << " : ";


		}


	}


}

Edited by the Author.

Edited by the Author.