#include <fstream>
#include <iostream>
#include <vector>
using namespace std;

int fr[10001];
int n;
int Max;
long long rez;

void read() {
    int i, x;
    ifstream f("pairs.in");
    f >> n;
    for (i = 1; i <= n; i++) {
        f >> x;
        if (x > Max)
            Max = x;
        fr[x]++;
    }
    f.close();
}

vector<int> fact[10001];

void solve() {
    int i, j, prod, nr;

    for (i = 2; i <= Max; i++)
        if (fact[i].size() == 0)
            for (j = i; j <= Max; j += i) 
                fact[j].emplace_back(i);

    rez = n * (n - 1) / 2;
    for (i = 2; i <= Max; i++) {
        prod = 1;
        for (j = 0; j < fact[i].size(); j++)
            prod = prod * fact[i][j];
        if (prod != i)
            continue;
        nr = 0;
        for (j = 2; j * i <= Max; j++)
            nr += fr[i * j];
        if (fact[i].size() & 1)
            rez -= nr;
        else rez += nr;
    }
}

void output() {
    ofstream g("pairs.out");
    g << rez;
    g.close();
}

int main() {
    read();
    solve();
    output();
    return 0;
}