#include <iostream>

#define int long long

using namespace std;
const int M = 1e6;

int n, ans, fr[M+5], mobius[M+5];
bool prime[M+5];

int32_t main()
{
    freopen("pairs.in", "r", stdin);
    freopen("pairs.out", "w", stdout);
    cin.tie(nullptr)->sync_with_stdio(0);

    for(int i=1; i<=M; i++)
        prime[i] = mobius[i] = 1;
    for(int i=2; i<=M; i++)
        if(prime[i]) {
            for(int j=i; j<=M; j+=i) {
                mobius[j] *= -1;
                prime[j] = 0;
            }
            prime[i] = 1;
            for(int j=i*i; j<=M; j+=i*i)
                mobius[j] = 0;
        }

    cin >> n;
    for(int i=1; i<=n; i++) {
        int x;
        cin >> x;
        fr[x] = 1;
    }

    for(int i=1; i<=M; i++) {
        if(!mobius[i])
            continue;

        int cnt = 0;
        for(int j=i; j<=M; j+=i)
            cnt += fr[j];

        ans += mobius[i] * cnt * (cnt - 1) / 2;
    }

    cout << ans;
    return 0;
}