#include <iostream>
#include <cmath>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <unordered_map>
#include <queue>
#include <set>
#include <unordered_set>
#include <complex>
#include <list>
#include <cassert>
#include <chrono>
#include <random>
#include <stack>
#include <iomanip>
#include <fstream>
using namespace std;
#define endl "\n"
// #define int long long
const int INF = 2 * 1e5 + 5;
const int MOD = 1e9 + 7;
void solve(){
int n;
cin >> n;
vector<int> a(n+1), pref(n+1);
pref[0] = 0;
for(int i = 1; i <= n; i++){
cin >> a[i];
pref[i] = pref[i-1] + a[i];
}
vector<int> dp(pref[n], 0), good(n+1, 1);
for(int i = 1; i <= n; i++){
for(int j = pref[n]; j >= a[i]; j--){
dp[j] = max(dp[j], dp[j-a[i]]);
}
dp[a[i]] = i;
for(int k = 2; k <= i; k++){
int sum = pref[i] - pref[i-k];
if(sum%2==1 || dp[sum/2] < i-k+1){
good[k] = 0;
}
}
}
vector<int> sol;
for(int i = 2; i <= n; i++){
if(good[i]){
sol.push_back(i);
}
}
sort(sol.begin(), sol.end());
cout << sol.size() << " ";
for(auto &i : sol){
cout << i << " ";
}
cout << endl;
}
int32_t main(){
ios_base::sync_with_stdio(false); cin.tie(nullptr);
int t = 1;
cin >> t;
while(t--) solve();
return 0;
}
