// Online C++ compiler to run C++ program online
#include <bits/stdc++.h>
using namespace std;
int main() {
     int t;
     cin>>t;
     while(t--)
     {
         long int n,m,c=0;
         cin>>n;
         int a[n];
         for(int i=0;i<n;i++)
         {
             cin>>m;
             a[i]=m;
         }
         for(int j=n-1;j>=0;j--)
         {
             for(int i=j-1;i>=0;i--)
             {
                 if((a[j]-a[i])==(j-i))
                 c++;
             }
         }
         cout<<c<<endl;
     }
 
    return 0;
}

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4
6
3 5 1 4 6 6
3
1 2 3
4
1 3 3 4
6
1 6 3 4 5 6