#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    cout << 2 << "\n";
    int a = n, b = n - 1;
    for (int i = 1; i < n; i++) {
      cout << a << " " << b << "\n";
      a = (a + b + 1) / 2;
      b--;
    }
  }
}
