#include<fstream.h>
#include<math.h>


 long v[100001],x[1000001],pc[1000001];

int prim(long x){
 long i;
  for(i=1;i<=sqrt(x);i++) if(x%pc[i]==0) return 0;
  return 1;
  }


int main(){
 int b;
 long n;
 long i,j,p,res=0,q,k,t;
 long max;
 pc[0]=2;
 pc[1]=2;
 pc[2]=3;

ifstream f("pairs.in");
ofstream g("pairs.out");
  f>>n;
  max=-1;
  for(i=1;i<=n;i++){   f>>q;
		       v[q]=1; if(q>max) max=q;
		   }

  for(i=2;i<=max;i++){

       for(j=1;j<=max/i;j++)
	    if(v[i*j]==1) x[i]++;


     p=i;
     b=0;

     if(prim(p)==1 && x[p]>=1){b=1; res=res+(x[i]*(x[i]-1))/2;pc[0]++; pc[pc[0]]=i;}
     if(x[p]>1 && b==0){
	 t=0;

      for(k=1;k<=sqrt(p);k++)
	 if(p%pc[k]==0){ if((p/pc[k])%pc[k]==0){ t=-1; break;}
			t++; p=p/pc[k];
			if(p==1) break;}

	      if(t==0){res=res+(x[i]*(x[i]-1))/2;  pc[0]++; pc[pc[0]]=i;}
	       else{
	  if(p==1) { if(t>0 && t%2==0) res=res-(x[i]*(x[i]-1))/2;
		       else if(t>0) res=res+(x[i]*(x[i]-1))/2;
		     }
		 }
	}

   }
g<<n*(n-1)/2 - res;

f.close();
g.close();
return 0;
}