#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    if (n == 2) {
      cout << "2\n1 2\n";
      continue;
    }
    vector<pair<int, int>> ans;
    int cur = n;
    for (int i = n - 1; i >= 1; --i) {
      ans.push_back(make_pair(i, cur));
      cur = (cur + i + 1) / 2;
    }
    cout << cur << '\n';
    for (auto i : ans) cout << i.first << ' ' << i.second << '\n';
  }
  return 0;
}
