#include<stdio.h>
#include<string.h>
long n,i,a[100050],f[1000050],x[1000050],j,max,s;
int main()
{
 freopen("pairs.in","r",stdin);
 freopen("pairs.out","w",stdout);
 scanf("%ld",&n);
 for(i=1;i<=n;++i)
    {scanf("%ld",&a[i]);
     if(a[i]>max)max=a[i];
     f[a[i]]++;}
 for(i=1;i<=max;++i)
    for(j=1;j<=max/i;++j)
       x[i]+=f[i*j];
 memset(f,0,sizeof(f));
 for(i=2;i<=max;++i)
    if(f[i]==0)
      for(j=1;j<=max/i;++j)
         {if(j%i==0)f[i*j]=-1;
          if(f[i*j]>-1)f[i*j]++;}
 for(i=2;i<=max;++i)
    if(f[i]>0)
      if(f[i]%2)s+=(x[i]*(x[i]-1)/2);
           else s-=(x[i]*(x[i]-1)/2);
 printf("%ld\n",s);
 return 0;
}