#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
 
#define LL long long
 
using namespace std;
 
int n,b[2333],f[2333][2333],s[2][2333];
 
const int mod=1000000007;
 
int main()
{
    int t;scanf("%d",&t);
    while(t--){
        scanf("%d",&n);
        for(int i=1;i<=n;i++)scanf("%d",&b[i]);
        for(int i=0;i<=n;i++)for(int j=0;j<=i;j++)f[i][j]=0;
        for(int i=0;i<=n;i++)s[0][i]=s[1][i]=0;
        f[0][0]=1;
        for(int i=1;i<=n;i++){
            s[i%2][0]=0;
            for(int j=1;j<=min(i,b[i]);j++){
              //for(int k=j-1;k<=min(i-1,b[i-1]);k++)f[i][j]+=f[i-1][k];
            f[i][j]=((s[(i%2)^1][min(i-1,b[i-1])]-s[(i%2)^1][min(j-1,b[i-1])]+mod)%mod+f[i-1][j-1])%mod;
            s[i%2][j]=(s[i%2][j-1]+f[i][j])%mod;
        }
        }
     //   for(int i=1;i<=n;i++){for(int j=0;j<=i;j++)printf("%d ",f[i][j]);printf("\n");}
        int ans=0;
        for(int i=1;i<=min(n,b[n]);i++)ans=(ans+f[n][i])%mod;
        printf("%d\n",ans);
    }
    return 0;
}