#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
const int N = 1e6 + 5;
#define int long long
#define MAX LONG_LONG_MAX
int ar[N];
void solve()
{
    int n;
    cin >> n;
    for (int i = 1; i <= n + 1; i++)
        ar[i] = 0;
    queue<int> q;
    for (int i = 2; i <= n / 2; i++)
    {
        if (!ar[i * 2])
        {
            ar[i] = 1;
            ar[i * 2] = 1;
            q.push(i);
            q.push(i * 2);
        }
    }
    cout << q.size() / 2 << " ";
    while (!q.empty())
    {
        cout << q.front() << " ";
        q.pop();
    }
    cout << endl;
}

signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    int tcase;
    cin >> tcase;

    while (tcase--)
        solve();

    return 0;
}