#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define len(v) (int)v.size()
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define pii pair<int, int>
#define vi vector<int>
#define vii vector<vector<int>>
#define vpii vector<pair<int, int>>
#define ull unsigned long long
//#define int long long
const int N = 1e6 + 1;
const int maxn = 5e6 + 10;
const int C = 20;
const int logn = 20;
const ll inf = 1e9;
const ll mod = 1e9 + 7;
const int M = 1e9;
const ull M2 = 998244353;
const ld eps = 1e-6;
using namespace std;

template<class T>
istream &operator>>(istream &in, vector<T> &a) {
    for (auto &i : a)
        in >> i;
    return in;
}

template<class T>
ostream &operator<<(ostream &out, vector<T> &a) {
    for (auto &i : a)
        out << i << ' ';
    return out;
}

ll gcd(ll a, ll b) {
    return b ? gcd(b, a % b) : a;
}

ll binpow(ll a, ll n, ll m) {
    if (n == 0ll) return 1ll;
    else if (n % 2 == 1) {
        return ((((binpow(a, n - 1ll, m) % m + m) % m) * a) % m + m) % m;
    } else {
        ll d = (binpow(a, n / 2, m) % m + m) % m;
        return ((d * d) % m + m) % m;
    }
}

void solve() {
    int n; cin >> n;
    vi a(n); cin >> a;
    int k = *max_element(all(a)) + 1;

    vector<vector<int>> del(k);
    for (int i = 1; i < k; ++i) {
        for (int j = i; j < k; j += i) {
            del[j].push_back(i);
        }
    }
    vector<int> cnt(k);
    vector<int> cntel(k, 0), boolel(k, 0);
    for (int i = 0; i < n; ++i)
        cntel[a[i]]++;
    for (int i = 0; i < n; ++i) {
        if (boolel[a[i]]) continue;
        for (int j : del[a[i]]) {
            cnt[j] += cntel[a[i]];
        }
        boolel[a[i]] = 1;
    }
    vector<long long> ans(k);
    for (int i = 0; i < k; ++i) {
        ans[i] = 1ll * cnt[i] * (cnt[i] - 1) / 2;
    }
    for (int i = k - 1; i >= 0; --i) {
        for (int j : del[i]) {
            if (j != i) {
                ans[j] -= ans[i];
            }
        }
    }
    cout << ans[1];
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    int T = 1;
    //cin >> T;
    while (T--)
        solve();
}