#include <fstream>
#include <cmath>
using namespace std;
int n,nr,p[205],e[1005];
long long rez;
int main()
{int sw,i,k,a;
 ifstream fin("pairs.in");
 ofstream fout("pairs.out");
  fin>>n;
   for(i=2;i<=1000;++i)
    {sw=1;
        for(k=2;k<=sqrt(i);++k)
         if(i%k==0)
          {sw=0;break;}
     if(sw)
      p[++nr]=i;
    }
  for(i=1;i<=n;++i)
  {fin>>a;
    for(k=1;k<=nr;++k)
     if(a%p[k]==0)
      e[k]++;
  }
  rez=n*(n-1);rez/=2;
  for(i=1;i<=1000;++i)
   rez-=(e[i]*(e[i]-1))/2;
   fout<<rez<<'\n';
    return 0;
}