#include <stdio.h>
#include <math.h>
#include <vector>

using namespace std;

const int pr[] = {0,2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,293,307,311,313,317,331,337,347,349,353,359,367,373,379,383,389,397,401,409,419,421,431,433,439,443,449,457,461,463,467,479,487,491,499,503,509,521,523,541,547,557,563,569,571,577,587,593,599,601,607,613,617,619,631,641,643,647,653,659,661,673,677,683,691,701,709,719,727,733,739,743,751,757,761,769,773,787,797,809,811,821,823,827,829,839,853,857,859,863,877,881,883,887,907,911,919,929,937,941,947,953,967,971,977,983,991,997,1009};
const int lm = 169;

#define mm 1000010
#define nm 100010
#define pb push_back

int n, i, v[nm], b[mm], j;
long long sol, s1;
vector <int> a[mm];


void read()

{
	scanf("%d ", &n);
	for (i=1; i<=n; ++i)
	{
		scanf("%d ", &v[i]);
	}
}


void findpd(int p)

{
	int i, y = p;
	for (i=1; i<=lm && pr[i] <= (sqrt(p)+1) && pr[i] <= (p/2); ++i)
	{
		if (p % pr[i] == 0)
		{
			a[p].pb(pr[i]);
			while (y % pr[i] == 0)
				y /= pr[i];
			++ b[pr[i]];
		}
	}
	if (a[p].size() == 0)
	{
		a[p].pb(p);
		b[p] ++;
	}
	else
	{
		if (y > 1)
		{
			a[p].pb(y);
			b[y] ++;
		}
	}
}


void solve()

{
	for (i=1; i<=n; ++i)
	{
		findpd(v[i]);
	}
	sol = 0;
	for (i=1; i<=n; ++i)
	{
		s1 = n;
		for (j=0; j<a[v[i]].size(); ++j)
		{
			s1 = s1 - b[a[v[i]][j]] + 1;
		}
		--s1;
		sol += s1;
	}
	sol /=2;
}


void write()

{
	printf("%lld\n", sol);
}


int main()

{
	freopen("pairs.in", "r", stdin);
	freopen("pairs.out","w",stdout);

	read();
	solve();
	write();

	return 0;
}