#include <fstream>
using namespace std;

ifstream cin("pairs.in");
ofstream cout("pairs.out");

#define int long long

int frv[1000001];
int rasp[1000001];

signed main()
{
    int n,i,j,a;
    cin>>n;
    for(i=1;i<=n;i++){
        cin>>a;
        frv[a]++;
    }
    for(i=1e6;i;i--){
		for(j=i;j<=1e6;j+=i)
			rasp[i]+=frv[j];
		rasp[i]=(rasp[i]*(rasp[i]-1))/2;
		for(j=2*i;j<=1e6;j+=i)
			rasp[i]-=rasp[j];
	}
	cout<<rasp[1];
    return 0;
}