#include<cstdio>
#include<fstream>
#include<bitset>
#include<algorithm>
using namespace std;
#define MAXX 1000010
bitset<MAXX> p,b;
int d[MAXX];
int main()
{
    FILE* si=fopen("pairs.in","r");
    FILE* so=fopen("pairs.out","w");
    long long n;
    fscanf(si,"%lli",&n);

    int v[n],i;
    int maxx=0;

    for(i=0;i<n;++i)
    {
        fscanf(si,"%i",&v[i]);
        if(v[i]>maxx)
            maxx=v[i];
    }
    p[1]=0;
    b[1]=1;
    int j;
    for(i=2;i<=maxx;++i)
    {
        if(p[i]==0)
        {
            d[i]=1;
            for(j=2;(i*j)<=maxx;++j)
            {
                p[i*j]=1;
                if(j%i==0)
                    b[i*j]=1;
                ++d[i*j];
            }
        }
    }
    //...............................................................
    long long cont;
    long long s;
    s=0;
    for(i=2;i<=maxx;++i)
    {
        if(b[i]==0)
        {
            cont=0;
            for(j=0;j<n;++j)
                if(v[j]%i==0)
                    ++cont;
            cont=cont*(cont-1);
            cont=cont/2;
            if(d[i]%2==0)
                s=s-cont;
            else
                s=s+cont;
        }
    }
    fprintf(so,"%lli",(n*(n-1))/2-s);
    fclose(so);
    fclose(si);
}