#include <bits/stdc++.h>
#define int long long
using namespace std;
int z[1000005];
int dp[1000005];
int prefix[1000005];
int cnt[1000005];
vector <int> q[1000005];
void solve(){
int a;
cin >> a;
for (int i=1;i<=a;i++){
cin >> z[i];
prefix[i]=prefix[i-1]+z[i];
}
int n=prefix[a];
for (int i=1;i<=prefix[a];i++){
dp[i]=0;
cnt[i]=1;
}
for (int i=1;i<=a;i++){
for (int s=n;s>=z[i];s--){
dp[s]=max(dp[s],dp[s-z[i]]);
}
dp[z[i]]=max(dp[z[i]],i);
for (int j=1;j<=a;j++){
int l=i-j+1;
if (l<=0){
break;
}
int sum=prefix[i]-prefix[l-1];
if (sum%2==1){
cnt[j]=0;
}else{
int p=sum/2;
if (dp[p]>=dp[sum]){
cnt[j]*=1;
}else{
cnt[j]=0;
}
}
}
}
vector <int> v;
for (int i=1;i<=a;i++){
if (cnt[i]){
v.push_back(i);
}
}
cout << v.size() << " ";
for (auto p:v){
cout << p << " ";
}
cout << "\n";
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t;
cin >> t;
while (t--){
solve();
}
return 0;
}
