//shitty code dont judge
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#include <complex>
#include <queue>
#include <set>
#include <unordered_set>
#include <list>
#include <chrono>
#include <random>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <string>
#include <cstring>
#include <vector>
#include <map>
#include <unordered_map>
#include <stack>
#include <iomanip>
#include <fstream>
#include <bitset>
#include <math.h>
#include <stdlib.h>
 
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef pair<int,int> p32;
typedef pair<ll,ll> p64;
typedef pair<double,double> pdd;
typedef vector<ll> v64;
typedef vector<int> v32;
typedef vector<vector<int> > vv32;
typedef vector<vector<ll> > vv64;
typedef vector<vector<p64> > vvp64;
typedef vector<p64> vp64;
typedef vector<p32> vp32;
ll MOD = 998244353;
double eps = 1e-12;
#define forn(i,e) for(ll i = 0; i < e; i++)
#define forsn(i,s,e) for(ll i = s; i < e; i++)
#define rforn(i,s) for(ll i = s; i >= 0; i--)
#define rforsn(i,s,e) for(ll i = s; i >= e; i--)
#define ln "\n"
#define dbg(x) cout<<#x<<" = "<<x<<ln
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define INF 2e9
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) ((ll)(x).size())

int tr[5005];
ll pek[5005], kount;


void solve(){
    memset(tr, 0, sizeof tr);
    memset(pek, 0, sizeof pek);
    kount = 0;

    int n;
    cin>>n;

    for(int i = 0; i < n; i++){
        cin>>tr[i];
    }
    
    for(int i = 0; i < n; i++){
        if(tr[i] == 1 && i < n-1){
            pek[i+1] += pek[i];
            continue;
        }
        
        if(tr[i] > pek[i] + 1){
            kount += tr[i] - pek[i] - 1;
        }
        else{
            pek[i+1] += pek[i] - tr[i] + 1;
        }

        for(int j = 2; j <= tr[i] && (i + j) < n; j++){
            pek[i + j]++;
        }
    }

    cout<<kount<<ln;
}
int main()
{

    ll t;
    cin >> t;
    for(int it=1;it<=t;it++) {
     //cout << "Case #" << it+1 << ": ";
        solve();
    }
    return 0;
}