Sieve of Eratosthenes C# implementation

SieveofEratosthenes.cs

long sum = 0;
long n = 2000000;
bool[] e = new bool[n];//by default they're all false
for (int i = 2; i < n; i++)
{
    e[i] = true;//set all numbers to true
}
//weed out the non primes by finding mutiples 
for (int j = 2; j < n; j++)
{
   if (e[j])//is true
   {
       for (long p = 2; (p*j) < n; p++)
       {
           e[p * j] = false;
       }
   }
}
//Uptill here e[] sorta of contains a list of primes
//the index represent the actual number and the value at the index represents if the number is prime
//Example:
//e[4], e[100] will all be false since 2,4,100 are not primes
//e[5], e[7], e[11], e[13] will all be true because 5,7,11,13 are all prime numbers

2 is the first prime number.

If you set the first for loop to start at 3 and increment by 2, you'll weed out even numbers (which aren't prime)

Weird things