#include <cstdio>

const int maxn = 100001;
const int maxp = 2000;

FILE *in = fopen("pairs.in","r"), *out = fopen("pairs.out","w");

int n;
int a[maxn];

int k;
char x[maxp];
int primes[maxp];

int maxnr;

void ciur()
{
    primes[++k] = 2;

    for ( int i = 4; i <= maxp; i += 2 )
        x[i] = 'x';

    for ( int i = 3; i <= maxp; i += 2 )
        if ( x[i] != 'x' )
        {
            primes[++k] = i;

            for ( int j = i+i; j <= maxp; j += i )
                x[j] = 'x';
        }
}

int e[maxn*10];
int h[maxn*10]; // h[i] = cate numere au ca factor prim i

void read()
{
    fscanf(in, "%d", &n);

    for ( int i = 1; i <= n; ++i )
        fscanf(in, "%d", &a[i]), ++e[ a[i] ], a[i] > maxnr ? maxnr = a[i] : 1;
}

void calch()
{
    for ( int i = 1; i <= maxnr; ++i )
        for ( int j = i; j <= maxnr; j += i )
            if ( e[j] )
                ++h[i];
}

long long count()
{
    long long res = 0;

    int nrp = 0;

    for ( int i = 2; i <= maxnr; ++i )
    {
        if ( x[i] != 'x' )
        {
            res = res + (long long)(h[i]*(h[i] - 1) / 2);
            continue;
        }

        int tmp = i;
        int ee = 0;
        int ok = 1;
        nrp = 0;

        for ( int j = 1; primes[j]*primes[j] <= i; ++j )
        {
            ee = 0;
            if ( tmp % primes[j] == 0 )
            {
                ++nrp;
                while ( tmp % primes[j] == 0 )
                    tmp /= primes[j], ++ee;

                if ( ee > 1 )
                {
                    ok = 0;
                    break;
                }
            }
        }

        if ( ok )
        {
            if ( nrp % 2 == 0 )
                res = res - (long long)(h[i]*(h[i] - 1) / 2);
            else
                res = res + (long long)(h[i]*(h[i] - 1) / 2);
        }
    }

    return res;
}

int main()
{
    ciur();
    read();
    calch();


    long long cnt = (long long)n*(n-1)/2;

    fprintf(out, "%lld\n", cnt - count());

	return 0;
}