#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <cstdlib>
using namespace std;

typedef long long LL;
const LL mod = 1000000007;
const int MAXN = 100010;
int a[MAXN];
LL dp[MAXN];

int main() {
    int T;
    scanf("%d", &T);
    while(T--) {
        int n;
        scanf("%d", &n);
        memset(dp, 0, sizeof dp);
        bool wr = false;
        for(int i = 1 ; i < n ; i++) {
            scanf("%d", &a[i]);
            if(i + a[i] > n) wr = true;
        }
        if(wr) {
            printf("0\n");
            continue;
        }
        for(int i = 2 ; i < n ; i++) {
            if(a[i] == a[i - 1] - 1 || a[i - 1] == 0);
            else wr = true;
        }
        if(wr) {
            printf("0\n");
            continue;
        }
        dp[n] = 26;
        for(int i = n - 1 ; i >= 1 ; i--) {
            if(a[i] == 0) dp[i] = (25 * dp[i + 1]) % mod;
            else {
                dp[i] = (dp[i + a[i]]) % mod;
            }
        }
        printf("%I64d\n", dp[1]);
    }
    return 0;
}