#include<stdio.h>
#include <math.h>
#define Nmax 1000009
#define L long long

int sol[1000],max,nr,i,j,n,m,prim[1000],c[Nmax];
bool ok[10000],a[Nmax];
L rez;

void ciur()
{
	int i,j;
	
	prim[nr=1]=2;
	
	for (i=3;i<=(int)sqrt(Nmax);i+=2)
		if (!ok[i])
		{
			prim[++nr]=i;
			for (j=i*i;j<=sqrt(Nmax);j+=(2*i))
				ok[j]=true;
		}
}

void back(int k,int p)
{
	int i;

	if (k%2==0) rez-=(c[p]*(c[p]-1)/2);
		else rez+=(c[p]*(c[p]-1)/2);
	
	for (i=sol[k-1]+1;i<=nr;i++)
	{
			sol[k]=i;
			if ((L)p*prim[i]<max) back(k+1,p*prim[i]);
	}
}

int main()
{
	freopen("pairs.in","r",stdin);
	freopen("pairs.out","w",stdout);
	
	scanf("%d",&n);
	
	for (i=1;i<=n;i++)
	{
		scanf("%d",&j);
		a[j]=true;
		if (j>max) max=j;
	}
	
	rez=(L)n*(n-1)/2;
	ciur();
	
	for (j=1;j<=max;j++)
		for (i=j;i<=max;i+=j)
			if (a[i]) c[j]++;
	c[1]=1;
	
	
	back(1,1);
	if (a[1]) rez=rez-n+1;
	
	printf("%lld\n",rez);
	return 0;
}