#include <cstdio>
#define DN 1000005
using namespace std;

int div[DN];

void descomp(int x)
{
	int f=2;
	while(x!=1)
	{
		int p=0;
		while(x%f==0)
		{
			x/=f;
			p++;
		}
		if(p) div[f]++;
		f++;
	}
}

int main()
{
	int n;
	unsigned long long rez=0;
	freopen("pairs.in","r", stdin);
	freopen("pairs.out","w", stdout);
	scanf("%d",&n);
	rez=n*(n-1)/2;
	for(int i=1;i<=n;i++)
	{
		int x;
		scanf("%d",&x);
	//	printf("%d ",x);
		descomp(x);
	}
	for(int i=1;i<=DN;i++)
	{
		rez-=div[i]*(div[i]-1)/2;
	}
	printf("%d",rez);

	return 0;
}