#include<bits/stdc++.h>

using namespace std;

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int t;
    cin >> t;
    while (t--) {
        int n;
        cin >> n;
        vector<int> a(n);
        for (auto &i: a)
            cin >> i;
        long long cur = 0;
        int start = 0;
        while(start < n){
            while(start < n && a[start] == 1)
                start++;
            if(start == n)
                break;
            if(a[start] + start >= n){
                cur += a[start] - max((n - start - 1), 1);
                a[start] = max(n - start - 1, 1);
            }
            while(a[start] > 1){
                int w = start;
                while(w < n) {
                    int prev = a[w];
                    a[w] = max(a[w] - 1, 1), w += prev;
                }
                cur++;
            }
        }
        cout << cur << '\n';
    }
}