#include <fstream>
using namespace std;
ifstream in("pairs.in");
ofstream out("pairs.out");
long long n,m,k,s,maxi,f[1000005],p[1000005],ok[1000005];
int main()
{ in>>n;
  for(long long i=1;i<=n;i++)
    in>>m,f[m]=1,maxi=max(maxi,m);
  for(int i=2;i<=1000000;i++)
    if(!ok[i])
    { p[i]=1;
      ok[i]=1;
      for(long long j=2*i;j<=1000000;j+=i)
      { ok[j]=1;
        p[j]++;
        if((j/i)%i==0)
           ok[j]=0;
      }
    }
  for(long long i=2;i<=maxi;i++)
  { if(!ok[i])
       continue;
    k=0;
    for(long long j=i;j<=maxi;j+=i)
      k+=f[j];
    if(p[i]%2==1)
       s+=k*(k-1)/2;
    else
       s-=k*(k-1)/2;
  }
  out<<n*(n-1)/2-s;
  in.close();
  out.close();
  return 0;
}