#include <bits/stdc++.h>
using namespace std;
long long dx[] = {-1, 0, 1, 0};
long long dy[] = {0, 1, 0, -1};
long long spf[1];
void sieve() {
  long long i, j;
  for (i = 0; i < 1; i++) spf[i] = i;
  for (i = 4; i < 1; i += 2) spf[i] = 2;
  for (i = 3; i * i < 1; i++) {
    if (spf[i] == i) {
      for (j = i * i; j < 1; j += i) {
        if (spf[j] == j) spf[j] = i;
      }
    }
  }
}
bool isvowel(char c) {
  switch (c) {
    case 'a':
    case 'e':
    case 'i':
    case 'o':
    case 'u':
    case 'y':
      return true;
    default:
      return false;
  }
}
bool cmp(pair<long long, long long> x, pair<long long, long long> y) {
  return x.first > y.first;
}
bool isPrime(long long n) {
  for (long long i = 2; i <= sqrt(n); i++) {
    if (n % i == 0) {
      return false;
    }
  }
  return true;
}
long long sum(long long n) {
  long long ans = 0;
  while (n > 0) {
    long long d = n % 10;
    ans += d;
    n /= 10;
  }
  return ans;
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long t;
  cin >> t;
  while (t--) {
    long long n;
    cin >> n;
    deque<long long> q;
    for (long long i = 1; i <= n; i++) {
      q.push_back(i);
    }
    cout << "2"
         << "\n";
    while (1) {
      if (q.size() == 1) {
        break;
      } else {
        long long a = q.back();
        q.pop_back();
        long long b = q.back();
        q.pop_back();
        cout << a << " " << b << "\n";
        long long x;
        if ((a + b) % 2) {
          x = ((a + b) / 2) + 1;
        } else {
          x = (a + b) / 2;
        }
        q.push_back(x);
      }
    }
  }
  return 0;
}
