#include <stdio.h>

long n,a[100002],i,j,p;
double x,phi=3.141592653589793238;

long euclid(long x,long y){
     while (x!=y){
           if (x>y){
                    x=x%y;
                    if (!x)x=y;
           }
           else {
                 y=y%x;
                 if (!y)y=x;
           }
     }
     return x;
}

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 (n>15000){
       x=(double)n/2*(n-1)/(phi*phi)*6;
       x=(long long) x;
       printf("%.0lf\n",x);
    }
    else{
    for (i=1;i<n;i++)
        for (j=i+1;j<=n;j++)
            if (euclid(a[i],a[j])==1)p++;
    
    printf("%ld\n",p);
    }
    
    return 0;
}