#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define veci vector <int>
#define ll long long
#define sz(_v) (int)_v.size()
const int MAXN = 1e5 + 10;
///const int MOD = 1e9 + 7;
unsigned int dp[MAXN];
int S, n;
int a[1010];
int pref[1010];
void del(int x) {
for(int i = x; i <= S; ++i) dp[i] -= dp[i - x];
///if(dp[i] < 0) dp[i] += MOD;
}
void add(int x) {
for(int i = S; i >= x; --i) dp[i] += dp[i - x];
///if(dp[i] >= MOD) dp[i] -= MOD;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t;
cin >> t;
dp[0] = 1;
for(int cs = 1; cs <= t; ++cs) {
cin >> n;
int gc = 0;
for(int i = 1; i <= n; ++i) {
cin >> a[i];
gc = __gcd(gc, a[i]);
}
for(int i = 1; i <= n; ++i) {
a[i] /= gc;
pref[i] = pref[i - 1] + a[i];
}
veci ans;
for(int len = 2; len <= n; ++len) {
char can = 1;
for(int i = 1; i + len - 1 <= n; ++i) {
if((pref[i + len - 1] - pref[i - 1]) % 2 != 0) {
can = 0;
break;
}
}
if(!can) continue;
multiset <int> st;
for(int i = 1; i <= len; ++i) st.insert(a[i]);
if(*st.rbegin() > pref[len] / 2) continue;
for(int i = len + 1; i <= n; ++i) {
st.erase(st.find(a[i - len]));
st.insert(a[i]);
if(*st.rbegin() > (pref[i] - pref[i - len]) / 2 || *st.begin() > (pref[i] - pref[i - len]) / 4) {
can = 0;
break;
}
}
if(!can) continue;
S = pref[len];
for(int l = 1; l <= len; ++l) add(a[l]);
if(dp[S >> 1] == 0) {
for(int i = 1; i <= S; ++i) dp[i] = 0;
continue;
}
for(int r = len + 1; r <= n; ++r) {
del(a[r - len]);
S -= a[r - len];
S += a[r];
add(a[r]);
if(dp[S >> 1] == 0) {
for(int i = 1; i <= S; ++i) dp[i] = 0;
can = 0;
break;
}
}
if(can) {
for(int i = 1; i <= S; ++i) dp[i] = 0;
ans.pb(len);
}
}
cout << sz(ans) << ' ';
for(auto it : ans) cout << it << ' ';
cout << '\n';
}
return 0;
}
