#include <fstream>

#define maxn 100001
#define maxv 1000001

using namespace std;

ifstream fin("pairs.in");
ofstream fout("pairs.out");

int a[maxn],n,t,prod=1;
int sieve[maxv],v[maxv];
int p[maxn],nr[maxn],maxval;
long long s;

void erathostenes ()
{
    for (int i=2; i<=maxval; ++i)
    {
        if (v[i])
        {
            if (!sieve[i]) p[++t] = i;
            nr[i] ++;
        }

        for (int j=i+i; j<=maxval; j+=i)
        {
            if (v[j])
            {
                if (!sieve[i] && !nr[i]) p[++t] = i;
                nr[i] ++;
            }

            sieve[j] = 1;
        }
    }
}

void back (int k, int cnt)
{
    if (prod > maxval)
        return;

    /*for (int i=k; i<=t; ++i)
    {
        prod *= p[i];
        back (i+1,cnt+1);
        prod /= p[i];
    }

    if (cnt%2)
    {
        s += nr[prod]*(nr[prod]-1)/2;
    }
    else
    {
        s -= nr[prod]*(nr[prod]-1)/2;
    }*/
}

int main()
{
    fin>>n;

    for (int i=1; i<=n; ++i)
    {
        fin>>a[i];
        v[a[i]]=1;

        maxval = max (a[i],maxval);
    }

    erathostenes ();

    back (1,0);

    fout<<1LL*n*(n-1)/2-s;
}