n^2 - 2. Is it prime?

n2 primer.cpp

#include <iostream>
using namespace std;

#define MAX 100

bool isPrime(const int i)
{
    if (i <= 1) return false;
    int j;

    for(j = 2; j*j <= i; j++)
        if(0 == i%j) return false;

    return true;
}


int main(void)
{
    bool p;
    char c;
    int n2;

    int odd;
    for (odd = 3; odd < MAX; odd += 2)
        {
        n2 = (odd * odd) - 2;
        p = isPrime(n2);
        c = p ? ' ' : '*';

        cout << odd << " : " << n2 << " " << c << "  " << endl;
        }

    return 0;
}