#include <iostream>
#include <vector>
using namespace std;
typedef long long ll;

std::vector<int> enum_prime(int n){     // containing n
    std::vector<int> res;
    if (n <= 1) return res;
    std::vector<bool> p(n + 1);
    fill(p.begin() + 2, p.end(), true);
    for(int i = 2; i <= n; i++){
        if(p[i]){
            res.push_back(i);
            for(int j = i * 2; j <= n; j += i) p[j] = false;
        }
    }
    return res;
}

int d[50000005];
ll b[50000005];

int main()
{
    int n;
    cin >> n;
    vector<int> prime = enum_prime(10000);
    for(int i = 1; i <= n; i++) d[i] = i;
    for(int p : prime){
        int q = p * p;
        for(int j = q; j <= n; j += q){
            while(d[j] % q == 0) d[j] /= q;
        }
    }
    for(int i = 1; i <= n; i++) b[d[i]]++;
    ll ans = 0;
    for(int i = 1; i <= n; i++) ans += b[i] * b[i];
    cout << ans << endl;
}