#include <bits/stdc++.h>
using namespace std;
int vec[1005], pref[1005], dp[1005][50005];
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int cases; cin >> cases;
while (cases--){
int nums; cin >> nums;
pref[0] = 0;
for (int i = 1; i <= nums; i++) cin >> vec[i];
for (int i = 1; i <= nums; i++) pref[i] = pref[i - 1] + vec[i];
vector<bool> ok(nums + 1, 1);
for (int i = 1; i <= nums; i++){
for (int sum = 0; sum < vec[i]; sum++) dp[i][sum] = dp[i - 1][sum];
for (int sum = vec[i]; sum < 50005; sum++) dp[i][sum] = max(dp[i - 1][sum], dp[i - 1][sum - vec[i]]);
dp[i][vec[i]] = i;
for (int j = 1; j <= i; j++){
int sum = pref[i] - pref[j - 1], sz = i - j + 1;
if (sum % 2) ok[sz] = 0;
else if (dp[i][sum / 2] < j) ok[sz] = 0;
}
}
int cnt = 0;
for (int i = 1; i <= nums; i++)
if (ok[i])
cnt++;
cout << cnt << ' ';
for (int i = 1; i <= nums; i++)
if (ok[i])
cout << i << ' ';
cout << '\n';
}
return 0;
}
