#include <bits/stdc++.h>
using namespace std;
int main() {
  int t, n;
  scanf("%d", &t);
  while (t--) {
    scanf("%d", &n);
    for (int i = n * 4, cnt = 1; cnt < n; cnt++, i -= 2) printf("%d ", i);
    printf("%d\n", n * 2 + 2);
  }
  return 0;
}
