#include <stdio.h>
#include <fstream>
#include <vector>
#include <iostream>
using namespace std;

#define in "pairs.in"
#define out "pairs.out"
#define dim 100001

int N, M=0;
int A[dim], C[dim*10]; // C[i] - numarul de numere din M care se divid cu i ( i >= 2 )
bool Sel[dim*10], Ok[dim*10];
vector<int> Div;

int main()
{
    // numere prime
    memset(Ok,0,sizeof(Ok));
    for ( int i = 2; i*i <= 1000001; i++ )
    {
        int j = 2;
        while ( i*j <= 1000001 ) Ok[i*j] = 1, j++;
    }
    
    for ( int i = 2; i <= 1000001; i++ )
    {
        C[i] = Sel[i] = 0;
        if ( Ok[i] == 0 ) Div.push_back(i);
    }
    //
    
    freopen(in,"r",stdin);
    freopen(out,"w",stdout);
    
    scanf("%d", &N);
    for ( int i = 1; i <= N; i++ )
    {
        scanf("%d", &A[i]);
        Sel[A[i]] = 1;
        if ( A[i] > M ) M = A[i];
    }
    
    for ( int i = 2; i <= M; i++ )
        for ( int j = 1; i*j <= M; j++ )
            if ( Sel[i*j] ) C[i] += 1;
    
    int Q, ok=0, S, K;
    long long T=0, Res=0, F = 0;
    
    for ( int i = 2; i <= M; i++ )
    {
        Q = i; S = 0; ok = 1;
        
        if ( C[i] <= 1 ) continue;
        
        for ( int j = 0; Div[j]*Div[j] <= Q; j++ )
        {
            K = 0;
            while ( Q % Div[j] == 0 ) Q /= Div[j], K += 1;
            
            if ( K > 1 ) 
            {
                 ok = 0;
                 break;
            }
            else if ( K == 1 ) S += 1;
        }
        
        if ( Q > 1 ) S += 1;
        
        if ( ok == 0 ) continue;
        
        F = C[i];
        F = F*(C[i]-1);
        F /= 2;
        
        if ( S % 2 == 0 ) Res -= F;
        else              Res += F;
    }
    
    T = N;
    T = T*(N-1);
    T /= 2;
    
    T -= Res;
    
    printf("%lld", T);
    
    return 0;
}