#include <cstdio>
#define ValMax 1000005

using namespace std;

bool fr[ValMax];
int cnt[ValMax],ciur[ValMax];

int main()
{
    int n,i,j,x;
    long long sol=0;
    freopen ("pairs.in","r",stdin);
    freopen ("pairs.out","w",stdout);
    scanf("%d", &n);
    for(i=1;i<=n;++i)
    {
        scanf("%d", &x); fr[x]=true;
    }
    for(i=1;i<=1000000;++i)
        for(j=i;j<=1000000;j+=i)
            if(fr[j]) ++cnt[i];
    for(i=2;i<=1000000;++i)
        if(!ciur[i])
        {
            sol+=1LL*cnt[i]*(cnt[i]-1)/2;
            for(j=i*2;j<=1000000;j+=i) ++ciur[j];
        }
        else
        {
            sol-=1LL*cnt[i]*(cnt[i]-1)/2*(ciur[i]-1);
            for(j=i*2;j<=1000000;j+=i) ciur[j]-=ciur[i]-1;
        }
    printf("%lld\n", 1LL*n*(n-1)/2-sol);
    return 0;
}