#include <bits/stdc++.h>
using namespace std;
#define MOD ((long long)pow(10,9)+7)

int main(){
  int n;
  cin>>n;
  vector<int> a(n);
  for(int i=0;i<n;i++){
    cin>>a[i];
  }
  vector<long long> dp(n,0);
  dp[0]=1;
  for(int i=0;i<n-1;i++){
    dp[i+1]=(dp[i]+dp[i+1])%MOD;
    for(int k=i+a[i];k<n;k+=a[i]){
      if (k==i+1) continue;
      dp[k]=(dp[i]+dp[k])%MOD;
    }
  }
  cout<<dp[n-1]<<"\n";
  return 0;
}