#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    vector<int> a(n);
    cout << 2 << endl;
    int prev = (n + n - 1) / 2;
    if ((n + n - 1) % 2 != 0) prev++;
    cout << n << " " << n - 1 << endl;
    for (int i = n - 2; i >= 1; i--) {
      int ad = 0;
      cout << i << " " << prev << endl;
      if ((i + prev) % 2 != 0) ad = 1;
      prev = (i + prev) / 2 + ad;
    }
  }
}
