#include <stdio.h>
#include <string.h>

#define MAX_VAL 1000005
#define FIN "pairs.in"
#define FOUT "pairs.out"
#define INF 0x3f3f3f3f
#define ll long long
#define min(a, b) ((a) < (b) ? (a) : (b))

int N, cnt[MAX_VAL], P[MAX_VAL], exp[MAX_VAL];
char ok[MAX_VAL]; ll Res;

int main(void)
{
    int i, j, x;

    freopen(FIN, "r", stdin);
    freopen(FOUT, "w" ,stdout);

    scanf("%d", &N);
    for (i = 0; i < N; ++i)
    {
        scanf("%d", &x);
        cnt[x]++;
    }
    
    Res = (ll)N*(N-1)/2;
    memset(P, 0x3f, sizeof(P));
    for (ok[1] = 1, i = 2; i < MAX_VAL; ++i)
    {
        for (j = 2*i; j < MAX_VAL; j += i)
            cnt[i] += cnt[j];
        if (P[i] == INF) P[i] = i;
        if ((i/P[i])%P[i] && ok[i/P[i]])
        {
            ok[i] = 1;
            exp[i] = 1^exp[i/P[i]];
            if (exp[i]&1)
                Res -= (ll)cnt[i]*(cnt[i]-1)/2;
            else
                Res += (ll)cnt[i]*(cnt[i]-1)/2;

        }
        for (j = 2*i; j < MAX_VAL; j += i)
            P[j] = min(P[j], P[i]);
    }
    printf("%lld\n", Res);

    return 0;
}