#include <bits/stdc++.h>
using namespace std;
inline void read(int& x) {
x = 0;
char ch = getchar_unlocked();
while (ch < '0' || ch > '9') ch = getchar_unlocked();
while (ch >= '0' && ch <= '9') {
x = (x << 3) + (x << 1) + (ch & 15);
ch = getchar_unlocked();
}
}
int main(){
int cases; read(cases);
while (cases--){
int nums; read(nums);
vector<int> vec(nums + 1), pref(nums + 1);
pref[0] = 0;
for (int i = 1; i <= nums; i++) read(vec[i]);
for (int i = 1; i <= nums; i++) pref[i] = pref[i - 1] + vec[i];
vector<vector<int>> dp(nums + 1, vector<int>(50005, -1));
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 sz = 1; sz <= nums; sz++)
for (int j = 1; j <= nums - sz + 1; j++){
int i = j + sz - 1, sum = pref[i] - pref[j - 1];
if (sum & 1) {
ok[sz] = 0;
break;
}
else if (dp[i][sum >> 1] < j) {
ok[sz] = 0;
break;
}
}
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;
}
