#include <iostream>
#include <vector>
using namespace std;
const int M = 50005;
int Mx[M], a[M];
int main(){
int n, t;
cin>>t;
while (t--){
cin>>n;
for (int i=1;i<=n;i++)
cin>>a[i];
vector<int> ans;
for (int j=1;j<M;j++)
Mx[j] = -1;
Mx[0] = 0;
for (int i=1, s = 0;i<=n;i++){
for (int j=min(M-1, a[i-1]);j+1;j--)
if (j + a[i] < M and Mx[j] > Mx[j + a[i]])
Mx[j+a[i]] = Mx[j];
Mx[a[i]] = i;
a[i] += a[i-1];
for (int j=0;j<ans.size();j++){
s = a[i] - a[i-ans[j]];
if (s % 2 == 1 or Mx[s / 2] <= i - ans[j])
ans.erase(ans.begin() + j), j--;
}
if (a[i] % 2 == 0 and Mx[a[i]/2] != -1)
ans.push_back(i);
}
cout<<ans.size()<<' ';
for (int i=0;i<ans.size();i++)
cout<<ans[i]<<' ';
cout<<'\n';
}
}
