#pragma GCC optimize ("Ofast")
#include <bits/stdc++.h>
using namespace std;
ifstream f("pairs.in");
ofstream g("pairs.out");

const int Max = 1e6 + 1;
void nos()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
}
int n;
vector < int > multime;
int maxx;
void read()
{
    f>>n;
    int i;
    for(i=1; i<=n; i++)
    {
        int x;
        f>>x;
        maxx = max(maxx,x);
        multime.push_back(x);
    }
}

int divisible[Max];
unsigned int  dp[Max];
vector < int > divi;
int ans = 1;
int last;
void bkt(int k)
{
    if( k == last)
    {
        divisible[ans] ++;
        return;
    }
    bkt(k+1);
    int aux = ans;
    ans*=divi[k];
    bkt(k+1);
    ans = aux;
}
void baga(int n)
{
    divi.clear();
    int d = 3;
    if(n%2 == 0)
    {
        while(n%2 == 0)
            n/=2;
        divi.push_back(2);
    }
    while(n!=1)
    {
        if(n%d == 0)
        {
            while(n%d == 0)
                n /= d;
            divi.push_back(d);
        }
        d+=2;
        if(d*d > n)
            break;
    }
    if(n!=1)
        divi.push_back(n);
    //    for(auto it : divi)
    //          cout<<it.first<<' '<<it.second<<'\n';
    last = divi.size();
    ans = 1;
    bkt(0);
}
void solve()
{
    for(auto it : multime)
        baga(it);
    //dp[i] nr de perechi care au cmmdc i
    //un fel de ciur invers?
    int i,j;
    for(i = maxx; i>= 1; i--)
    {
        int val = divisible[i];
        dp[i] = (val*(val-1)) / 2;
        for(j=2; j<=maxx / i; j++)
            dp[i] -= dp[i*j];
        //scadem multipli, principiul includerii excluderii
    }
    g<<dp[1];
}
void restart()
{

}

int32_t main()
{

    read();
    solve();
    restart();
    return 0;
}