#include #include #include #include #include #include #include #include #include #include #include #define rep(i,n) for(int i = 0; i < n; ++i) #define rep1(i,n) for(int i = 1; i <= n; ++i) using namespace std; templatebool chmax(T &a, const T &b) { if(a < b){ a = b; return 1; } return 0; } templatebool chmin(T &a, const T &b) { if(a > b){ a = b; return 1; } return 0; } template inline int sz(T &a) { return a.size(); } using ll = long long; using ld = long double; using pi = pair; using pl = pair; using vi = vector; using vvi = vector; using vl = vector; using vvl = vector; const int inf = numeric_limits::max(); const ll infll = numeric_limits::max(); // Modint // modint で宣言 template struct modint{ ll x; ll mod = MOD; modint(ll x=0):x(x%MOD){} modint& operator+=(const modint a){ if((x+=a.x)>=MOD) x-=MOD; return *this; } modint& operator-=(const modint a){ if((x += MOD-a.x)>=MOD) x-=MOD; return *this; } modint& operator*=(const modint a){ (x*=a.x)%=MOD; return *this; } modint operator+(const modint a) const{ modint res(*this); return res+=a; } modint operator-(const modint a) const{ modint res(*this); return res-=a; } modint operator*(const modint a) const{ modint res(*this); return res*=a; } modint pow(ll t) const{ if(!t) return 1; modint a = pow(t>>1); a*=a; if(t&1) a*=*this; return a; } //for prime mod modint inv() const{ return pow(MOD-2); } modint& operator/=(const modint a){ return (*this) *= a.inv(); } modint operator/(const modint a) const{ modint res(*this); return res/=a; } }; using mint = modint<1000000007>; int main() { ll n; cin >> n; vl a(n); rep(i,n) cin >> a[i]; ll m = sqrt(n); vector> sum(m+1, vector(m+1)); vector dp(n+2); dp[1].x = 1; rep1(i,n) { rep1(j,m) { int k = i % j; dp[i] += sum[j][k]; } if(a[i-1] <= m) { sum[a[i-1]][i%a[i-1]] += dp[i]; } else { ll id = i + a[i-1]; while(id <= n) { dp[id] += dp[i]; id += a[i-1]; } } if(a[i-1] != 1) dp[i+1] += dp[i]; } // rep1(i,n) cout << i << ":" << dp[i].x << "\n"; cout << dp[n].x << "\n"; return 0; }