#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define up(i, a, b) for (int i = (a); i <= (b); i++)
#define dn(i, a, b) for (int i = (a); i >= (b); i--)
typedef long long ll;
#define int long long
inline int read()
{
    int x = 0, f = 1;
    char ch = getchar();
    while (ch < 48 || ch > 57)
    {
        if (ch == '-')
            f = -1;
        ch = getchar();
    }
    while (ch >= 48 && ch <= 57)
    {
        x = (x << 1) + (x << 3) + (ch ^ 48);
        ch = getchar();
    }
    return x * f;
}
inline void write(int x)
{
    if (x < 0)
    {
        putchar('-');
        x = -x;
    }
    if (x > 9)
        write(x / 10);
    putchar(x % 10 + '0');
}
const int N = 1e5 + 10;
int a[N];
int t[N];
int k[N];

vector<int> vec[N];
map<int, int> mp;
int cnt = 0;
void solve()
{
    mp.clear();
    int n;
    cin >> n;
    cnt = 0;
    up(i, 1, n)
    {
        cin >> a[i];
        t[i] = a[i] - i;
        k[i] = 0;
    }
    up(i, 1, n)
    {
        if (mp.count(t[i]) == 0)
        {
            mp[t[i]] = ++cnt;
            vec[cnt].clear();
            k[cnt] = (t[i] << 1);
            vec[cnt].push_back(i);
        }
        else
        {
            vec[mp[t[i]]].push_back(i);
        }
    }

    int ans = 0;
    for (int i = 1; i <= cnt; i++)
    {
        int cont = 0;
        int cans = 0;
        for (auto it = vec[i].rbegin(); it != vec[i].rend(); it++)
        {
            cont++;
            cans += *it;
            if (cont == 2)
            {
                if (cans + k[i] > 0)
                    ans += cans + k[i];
                else
                    break;
                cont = 0;
                cans = 0;
            }
        }
    }
    cout << ans << endl;
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    int t;
    cin >> t;
    while (t--)
        solve();

    return 0;
}