#include <fstream>

using namespace std;
int n,i,j,ap,nr,sol,d,p,e,maxim,v[100001],f[1000001],x[1000001];
ifstream fin ("pairs.in");
ofstream fout ("pairs.out");

int main (){

    fin>>n;
    for (i=1;i<=n;i++){
        fin>>v[i];
        f[v[i]] = 1;
        maxim = max (maxim,v[i]);
    }
    for (i=2;i<maxim;i++)
        if (x[i] == 0)
            for (j=i;j<=maxim;j+=i) // aici vedem cati factori primi sunt in descompunerea unui nr
                x[j]++;
    for (i=2;i*i<=maxim;i++)
        for (j=i*i;j<=maxim;j+=i*i)
            x[j] = -1;
    for (i=2;i<=maxim;i++){
        if (x[i] == -1) continue;
        nr = 0;
        for (j=i;j<=maxim;j+=i)
            if (f[j] == 1)
                nr++;
        if (x[i]%2 == 0)
            sol -= nr*(nr-1)/2;
        else
            sol += nr*(nr-1)/2;
        //x[i] = ap; // nr de nr care se divid cu i, din v
        // il descompunem pe i in factori primi
        /*if (x[i] != 0){
            d = 2;
            p = i;
            nr = 0;
            while (p!=1 && d*d<=p){
                e = 0;
                while (p%d == 0){
                    p/=d;
                    e++;
                }
                if (e == 1)
                    nr++;
                if (e > 1){
                    nr = -2;
                    break;
                }
                d++;
            }
            if (p != 1)
                nr++;
            // nr = numarul de numere prime din descompunere care apar de maxim odata
            if (nr > 0){
                if (nr%2 == 0){
                    // scadem
                    sol -= x[i]*(x[i]-1)/2;
                }
                else{
                    sol += x[i]*(x[i]-1)/2;
                }
            }
        }*/
    }
    fout<<n*(n-1)/2 - sol;


    return 0;
}