#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
using namespace std;

ifstream f("pairs.in");
ofstream g("pairs.out");

long long n, ma=0, x, fr[1000000], ans[1000000];

int main()
{
    f>>n;
    for(int i=1; i<=n; i++)
    {
        f>>x;
        fr[x]++;
        ma = max(ma, x);
    }
    for(int cm=ma; cm>=1; cm--)
    {
        for(int i=cm; i<=ma; i=i+cm)
            ans[cm]=ans[cm]+fr[i];

        ans[cm] = ans[cm]*(ans[cm]-1)/2;
        for(int i = 2*cm; i<=ma; i=i+cm)
            ans[cm]=ans[cm]-ans[i];
    }
    g<<ans[1];
    return 0;
}