#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int NRMAX = 1e6;

int n, x, fr[NRMAX + 1], nrdivpr[NRMAX + 1];
bool bad[NRMAX + 1];

int main()
{
    freopen("pairs.in", "r", stdin);
    freopen("pairs.out", "w", stdout);
    scanf("%d", &n);
    for(int i = 1; i <= n; ++i) scanf("%d", &x), ++fr[x];
    ll ans = n * (n - 1) / 2;
    for(int i = 2; i <= NRMAX; ++i)
        if(!bad[i]) {
            ll crt = 0;
            for(int j = i; j <= NRMAX; crt += fr[j], j += i)
                if(!nrdivpr[j]) {
                    ++nrdivpr[j];
                    if(1ll * j % (i * i) == 0) bad[j] = 1;
                }
            if(nrdivpr[i] % 2) ans -= crt * (crt - 1) / 2;
            else ans += crt * (crt - 1) / 2;
        }
    printf("%lld", ans);
    return 0;
}