#include <bits/stdc++.h>
using namespace std;
void solve() {
const int C = 50001;
int n; cin >> n;
vector<int> dp(C, -1); dp[0] = -1;
vector<int> k(n - 1);
iota(k.begin(), k.end(), 2);
vector<int> a(n), pr(n + 1);
for (int i = 0; i < n; i++) { cin >> a[i]; pr[i+1]=pr[i]+a[i]; }
auto sum = [&](int l, int r) {return pr[r + 1] - pr[l]; };
if (a[0] < C) dp[a[0]] = 0;
for (int i = 1; i < n; i++) {
for (int x = 0; x + a[i] < C; x++) {
dp[x + a[i]] = max(dp[x + a[i]], dp[x]);
}
if (a[i] < C) dp[a[i]] = i;
vector<int> now; //cout << ":: ";
for (int x : k) {
int j = i - x + 1;
if (j < 0) {now.push_back(x); continue;}
int s = sum(j, i);
if (s % 2 == 0 && dp[s / 2] >= j) now.push_back(x);
//cout << x << ' ';
}
k = now; //cout << endl;
}
cout << (int)k.size() << endl; for (int x : k) cout << x << ' '; cout << endl;
}
int main() {
int test; cin>>test; while (test--){
solve();
}
}
