#include <bits/stdc++.h>
#define maxN 1000005
using namespace std;
int p[maxN],ap[maxN];
int mobius[maxN];
int n,maxx,i,j,x,val;
long long sol;
bool seen[maxN];
int main()
{
    freopen("pairs.in","r",stdin);
    freopen("pairs.out","w",stdout);
    scanf("%d",&n);
    for(i=1;i<=n;i++)
        scanf("%d",&j),
        seen[j]=true,
        maxx=max(maxx,j);
    for(i=2;i<=maxx;i++)
        if(!p[i])
            for(j=i;j<=maxx;j+=i)
                p[j]=i;
    mobius[1]=1;
    for(i=2;i<=maxx;i++)
        if(p[i]!=p[i/p[i]])
            if(mobius[i/p[i]]==1)
                mobius[i]=-1;
            else mobius[i]=1;
    for(i=1;i<=maxx;i++)
        if(mobius[i])
        {
            val=0;
            for(j=i;j<=maxx;j+=i)
                if(seen[j])
                    val++;
            sol+=mobius[i]*(val*(val-1))/2;
        }
    printf("%lld",sol);
    return 0;
}