#include <bits/stdc++.h>
using namespace std;

ifstream fin("pairs.in");
ofstream fout("pairs.out");

int main() {
    int n; fin >> n;
    vector<bool> mat(1e6 + 1);

    vector<int> frq(1e6 + 1);
    for (int i = 0; i < n; i++) {
        int x; fin >> x; mat[x] = true;
        vector<int> div;
        for (int j = 2; x > 1; j++)
            if (x % j == 0) {
                div.push_back(j);
                while (x % j == 0)
                    x /= j;
            }
        for (int mask = 1; mask < (1 << div.size()); mask++) {
            int prd = 1, cnt = 0;
            for (int bit = 0; bit < (int) div.size(); bit++)
                if (mask & (1 << bit)) {
                    prd *= div[bit];
                    cnt++;
                }
            frq[prd] += (cnt % 2 ? +1 : -1);
        }
    }

    vector<int> dp(1e6 + 1, n);
    for (int i = 2; i * i <= 1e6; i++)
        for (int j = i; j <= 1e6; j += i)
            dp[j] -= frq[i];

    int64_t sol = 0;
    for (int i = 1; i <= 1e6; i++)
        if (mat[i])
            sol += dp[i];
    fout << sol / 2 << '\n';

    fout.close();
    return 0;
}