#include <cstdio>

using namespace std;
long long n,x,m,i,j,nr,s,a[1000005],v[1000005],r[1000005];
int main()
{
    freopen("pairs.in","r",stdin);
    freopen("pairs.out","w",stdout);
    scanf("%lld",&n);
    for(i=1; i<=n; i++)
    {
        scanf("%lld",&x);
        a[x]=1;
        if(x>m) m=x;
    }
    for(i=2; i<=m; i++) r[i]=i;
    i=2;
    while(i*i<=m)
    {
        if(v[i]==0)
        {
            for(j=i; j<=m; j+=i)
            {
                if(j%(i*i)==0) v[j]=-1;
                else if(v[j]>=0)
                {
                    v[j]++;
                    r[j]/=i;
                }
            }
        }
        i++;
    }
    for(i=2; i<=m; i++)
    {
        if(v[i]>=0&&r[i]>1) v[i]++;
    }
    for(i=2; i<=m; i++)
    {
        if(v[i]>0)
        {
            nr=0;
            for(j=i; j<=m; j+=i) nr+=a[j];
            s+=(nr*(nr-1)/2)*((2*v[i])%4-1);
        }
    }
    printf("%lld\n",n*(n-1)/2-s);
    return 0;
}