#include <iostream>
using namespace std;
int dp[1<<17], cnt[1<<10], a[1<<10], mod = 1e9 + 7;
void Add(int &A, int B){
A += B;
if (A >= mod)
A -= mod;
}
int main(){
int t, n, ans;
cin>>t;
while (t--){
cin>>n;
for (int i=1;i<=n;i++)
cin>>a[i];
dp[1] = 1, ans = 0;
for (int k=2;k<=n;k++){
int s = 0;
cnt[k] = k - 1;
for (int i=1;i<=n+k;i++){
if (i > k){
for (int j=a[i-k];j <= s;j++)
Add(dp[j], mod - dp[j - a[i-k]]);
s -= a[i - k];
}
if (i <= n){
for (int j=s;j + 1;j--)
Add(dp[j+a[i]], dp[j]);
s += a[i];
}
if (i >= k and i <= n and (s & 1) == 0)
cnt[k] += (dp[s / 2] > 0);
}
ans += cnt[k] == n;
}
cout<<ans<<' ';
for (int k=1;k<=n;k++)
if (cnt[k] == n)
cout<<k<<' ';
cout<<'\n';
}
}
