#include<fstream>
#include<assert.h>

using namespace std;

#define max_n 1000100

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

int n , x , max_v , k , ok;
bool Fr[max_n] , V[max_n];
int Prim[max_n];
long long nr , prod;


void read(){
	
	f>>n;
	
	for( int i = 1 ; i <= n ; i++ ){
		f>>x; Fr[x] = 1;
		if( x > max_v )
			max_v = x;
	}
	
}

int desc( int i , long long& prod ){
	
	int nr = 0;
	
	prod = 1;
	
	for( int j = 0 ; j < k ; j++ ){
		if( i & (1<<j) ){
			nr++;
			prod *= Prim[j+1];
		}
	}
	
	return nr%2;
}

int main(){
	
	read();
	
	int i , j;
	
	for( i = 2 ; i <= max_v ; i++ ){
		if( V[i] == 0 ){
			Prim[++k] = i;ok = 1;
			for( j = i ; j <= max_v ; j += i ){
				V[j] = 1;
				if( Fr[j] )
					ok = 0;
			}
			if(ok)
				k--;
		}
	}
	
	long long total = (n-1)*n/2;
	
	for( i = 1 ; i < (1<<k) ; i++ ){
		ok = desc(i , prod); nr = 0;
		
		if( prod < 0 || prod > max_v )
			continue;
		
		for( j = prod ; j <= max_v ; j += prod ){
			if( Fr[j] )
				nr++;
		}
		
		if( ok )
			total -= (nr*(nr-1))/2;
		else
			total += (nr*(nr-1))/2;
	}
	
	g<<total;
	
	return 0;
}