#include <fstream>

using namespace std;

ifstream f("pairs.in");
ofstream g("pairs.out");

int n, fr[1000005], dp[1000005], valMax, x;

int main()
{
    f >> n;

    for (int i = 1; i <= n; ++i) {
        f >> x;

        fr[x]++;
        valMax = max(valMax, x);
    }

    for (int i = valMax; i >= 1; --i) {
        for (int j = i; j <= valMax; j += i) {
            dp[i] += fr[j];
        }

        dp[i] = (dp[i] * (dp[i] - 1) / 2);

        for (int j = i * 2; j <= valMax; j += i) {
            dp[i] -= fr[j];
        }
    }

    g << dp[1];

    return 0;
}