#include <bits/stdc++.h>
using i64 = long long;
#define ONLINE_JUDGE
void solve() {
int n;
std::cin >> n;
std::vector<int> a(n + 1);
for(int i = 1; i <= n; i++) {
std::cin >> a[i];
}
int sum = 0;
std::vector<int> dp(1), ans(n + 1, true);
for(int i = 1; i <= n; i++) {
sum += a[i];
dp.resize(sum + 1, -1);
for(int j = sum; j >= a[i]; j--) {
dp[j] = std::max(dp[j], dp[j - a[i]]);
}
dp[a[i]] = i;
/*
for(int i = 0; i <= sum; i++) {
std::cerr << dp[i] << " \n"[i == sum];
}
*/
int ssum = 0;
for(int j = i; j >= 1; j--) {
ssum += a[j];
ans[i - j + 1] &= (ssum % 2 == 0 && dp[ssum / 2] >= j);
}
}
std::vector<int> pr;
for(int i = 1; i <= n; i++) {
if(ans[i]) {
pr.emplace_back(i);
}
}
std::cout << int(pr.size()) << " ";
for(int &i : pr) {
std::cout << i << " ";
}
std::cout << "\n";
return;
}
signed main() {
#ifndef ONLINE_JUDGE
freopen("in.txt", "r", stdin);
freopen("out.txt", "w", stdout);
#endif
std::ios_base::sync_with_stdio(false);
std::cin.tie(NULL); std::cout.tie(NULL);
int t = 1; std::cin >> t;
for(int i = 1; i <= t; i++) {
solve();
}
return 0;
}
