#include <fstream>

using namespace std;

ifstream f("pairs.in");
ofstream g("pairs.out");

const int MAX_N = 100005;
const int MAX_VAL = 1000000;

int n, a[MAX_N], prime[MAX_VAL], nrprimes, NIVEL;
long long rez;
int X[MAX_VAL], cnt[MAX_VAL];		// X[i] = cate numere din M sunt divizibile cu i
bool frecv[MAX_VAL], prim[MAX_VAL + 5], bad[MAX_VAL];

void ciur() {
	for (int i = 2; i <= MAX_VAL; i++)
		prim[i] = 1;
	
	for (int i = 2; i * i <= MAX_VAL; i++)
		if (prim[i]) {
			for (int j = i * i; j <= MAX_VAL; j += i)
				prim[j] = 0;
		}
		
	for (int i = 2; i <= MAX_VAL; i++)
		if (prim[i])
			prime[++nrprimes] = i;
}

void read() {
	f >> n;
	for (int i = 1; i <= n; i++) {
		f >> a[i];
		frecv[a[i]] = 1;
	}
}

void precompute() {
	for (int i = 2; i <= MAX_VAL; i++) {
		for (int j = i; j <= MAX_VAL; j += i)
			if (frecv[j])
				X[i]++;
	}
	
	for (int i = 2; i <= MAX_VAL; i++) {
		if (prim[i])
			for (int j = i; j <= MAX_VAL; j += i)
				cnt[j]++;		// factorul prim i apare in descompunerea lui j
	}
}

void solve() {
	for (int i = 2; i <= MAX_VAL; i++)
		if (X[i]) {
			if (cnt[i] % 2 == 0)
				rez -= 1LL * X[i] * (X[i] - 1) / 2;
			else
				rez += 1LL * X[i] * (X[i] - 1) / 2;
		}
		
	rez = 1LL * n * (n - 1) / 2 - rez;
}
	
int main() {
	ciur();
	read();
	precompute();
	solve();
	
	g << rez << '\n';
	
	f.close();
	g.close();
	
	return 0;
}