#include<bits/stdc++.h>
#define god dimasi5eks
#pragma GCC optimize("O3")
#define fi first
#define se second
#define pb push_back
#define pf push_front
 
// #define fisier 1
 
using namespace std;
 
typedef long long ll;
 
const int mod = 1000000007;
const double dancila = 3.14159265359; // PI 
const double eps = 1e-9;
 
int n, fr[1000002], val;

ll cnt[1000002], ans;

void ciur()
{
	for(int i = 1000000; i >= 2; --i)
	{
		val = 0;
		for(int j = i; j <= 1000000; j += i)
			val += fr[j];
		cnt[i] = val * (val-1) / 2;
		for(int j = i+i; j <= 1000000; j += i)
			cnt[i] -= cnt[j];
		ans -= cnt[i];
	}
} 
int main()
{
	#ifdef fisier
		ifstream cin("pairs.in");
		ofstream cout("pairs.out");
	#endif
	
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	cin >> n;
	for(int i = 1; i <= n; ++i)
	{
		cin >> val;
		fr[val]++;
	}
	ans = n * (n-1) / 2;
	
	ciur();
	
	cout << ans;
	return 0;
}