#include <bits/stdc++.h>
//#pragma GCC optimize ("03")
#define FastIO ios_base::sync_with_stdio(false) , cin.tie(0) , cout.tie(0)
#define FILES freopen("pairs.in" , "r" , stdin) , freopen("pairs.out" , "w" , stdout)
#define ll long long
#define ull unsigned long long
#define ld long double
#define eb emplace_back
#define pb push_back
#define qwerty1 first
#define qwerty2 second
#define qwerty3 -> first
#define qwerty4 -> second
#define umap unordered_map
#define uset unordered_set
#define pii pair < ll , ll >
#define pq priority_queue
#define dbg(x) cerr << #x << ": " << x << '\n'

namespace FastRead
{
    char __buff[5000];ll __lg = 0 , __p = 0;
    char nc()
    {
        if(__lg == __p){__lg = fread(__buff , 1 , 5000 , stdin);__p = 0;if(!__lg) return EOF;}
        return __buff[__p++];
    }
    template<class T>void read(T&__x)
    {
        T __sgn = 1; char __c;while(!isdigit(__c = nc()))if(__c == '-')__sgn = -1;
        __x = __c - '0';while(isdigit(__c = nc()))__x = __x * 10 + __c - '0';__x *= __sgn;
    }
}

using namespace FastRead;
using namespace std;

const ll N = 1e6 + 10;
const ll M = 1e9 + 7;
const ld PI = acos(-1);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int n;
int fr[N] , cnt[N] , base[N] , nr[N];

signed main()
{
	#ifndef ONLINE_JUDGE
		FastIO , FILES;
	#endif

	ll i , j;

    cin >> n;

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

    ll ans = 1ll * n * (n - 1) / 2;

    for(i = 2 ; i < N ; i++)
    {
        if(base[i] == 1)
            continue;

        if(cnt[i] == 0)
        {
            for(ll j = i ; j < N ; j += i)
                cnt[j]++;

            for(ll j = i * i ; j < N ; j += i * i)
                base[j] = 1;
        }

        for(ll j = i ; j < N ; j += i)
            nr[i] += fr[j];

        ans -= 1ll * (cnt[i] % 2 ? +1 : -1) * nr[i] * (nr[i] - 1) / 2;
    }

    cout << ans;

    return 0;
}