#include <cstdio>
#include <cstring>

#define VMAX 1000050LL

char P[VMAX], exp[VMAX], viz[VMAX];
long long nr[VMAX], x, n, i, j, sol;

int main () {
	
	freopen ("pairs.in", "r", stdin);
	freopen ("pairs.out", "w", stdout);
	
	scanf ("%lld", &n);
	for (i = 1; i <= n; i++) {
		scanf ("%lld", &x);
		nr[x]++;
	}
	
	sol = (long long) n * (long long) (n-1) / 2LL;
	for (i = 2; i < VMAX; i++) {
		for (j = 2 * i; j < VMAX; j += i)
			nr[i] += nr[j];
		
		if (!P[i]) {
			exp[i] = 1;
			for (j = 2 * i; j < VMAX; j += i) {
				P[j] = 1;
				if ((j/i) % i == 0) viz[j] = 1;
				exp[j] ^= 1;
			}
		}
		
		if (viz[j] == 1) continue;
		
		if (exp[i])
			sol -= ((long long) nr[i] * (long long) (nr[i]-1) / 2LL);
		else
			sol += ((long long) nr[i] * (long long) (nr[i]-1) / 2LL);
	}
	
	printf ("%lld\n", sol);
	
	return 0;
}