#include <bits/stdc++.h>
using namespace std;
const long long int inf = 2e9;
const long long int N = 200005;
const long long int M = 100002;
long long int power(long long int x, long long int y, long long int p) {
  long long int res = 1;
  x = x % p;
  while (y > 0) {
    if (y & 1) res = (res * x) % p;
    y = y >> 1;
    x = (x * x) % p;
  }
  return res;
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  long long int ttt;
  cin >> ttt;
  while (ttt--) {
    long long int n;
    cin >> n;
    long long int val = 4 * n;
    bool flag = true;
    for (long long int i = 1; i <= n; i++) {
      if (flag) {
        cout << val << ' ';
      } else {
        cout << val - 2 << ' ';
        val -= 4;
      }
      flag = !flag;
    }
    cout << "\n";
  }
}
