$#doanthevu$

Code C++ :

#include <bits/stdc++.h>
#define ll long long
using namespace std;
 ll aa( ll N) 
{ return N * (N + 1) * (2 * N + 1) / 6; }
int main() 
{
    ll T;
    cin >> T;
    while (T--) {
         ll N;
        cin >> N;
        ll sum = aa(N);
        cout << sum << "\n";
    }
    return 0;
}

Công thức tính: $\frac{n(n + 1)(2n +1)}{6}$ $\\$$\\$

Code Python 

import sys

sys.stdin = open('TONGBP.INP', 'r')

sys.stdout = open('TONGBP.OUT', 'w') $\\$$\\$

def TBP(N):

    return N * (N + 1) * (2 * N + 1) // 6 $\\$$\\$

T = int(input())

for i in range(T):

    N = int(input())

    print(TBP(N))

$\\$$\\$

C++

#include <bits/stdc++.h>

using namespace std;

int main() 

{

  freopen("TONGBP.INP", "r", stdin);

  freopen("TONGBP.OUT", "w", stdout);

  int T; cin >> T;

  for (int i = 1; i <= t; i ++)

  {

    int N; cin >> N;

    cout << (N * (N + 1) * (2*N + 1)) / 6 << endl;

  }

}