#include using namespace atcoder; #include #define all(a) (a.begin()),(a.end()) #define rall(a) (a.rbegin()),(a.rend()) using namespace std; using ll=long long; using ld=long double; using pll=pair; templatebool chmax(T &a, const T &b) {if(abool chmin(T &a, const T &b) {if(b> (istream& is, modint1000000007& x) { unsigned int t; is >> t; x=t; return is; } istream& operator >> (istream& is, modint998244353& x) { unsigned int t; is >> t; x=t; return is; } istream& operator >> (istream& is, modint& x) { unsigned int t; is >> t; x=t; return is; } ostream& operator << (ostream& os, const modint1000000007& x) { os << x.val(); return os; } ostream& operator << (ostream& os, const modint998244353& x) { os << x.val(); return os; } ostream& operator << (ostream& os, const modint& x) { os << x.val(); return os; } templateistream& operator >> (istream& is, pair& p) { is >> p.first >> p.second; return is; } templateostream& operator << (ostream& os, const pair& p) { os << p.first << " " << p.second; return os;} templateistream& operator >> (istream& is, vector& v) { for(T& x:v) is >> x; return is; } templateostream& operator << (ostream& os, const vector& v) {for(int i=0;i void pt() { std::cout << "\n"; } template void pt_rest() { std::cout << "\n"; } template void pt_rest(const T& first, const A&... rest) { std::cout << " " << first; pt_rest(rest...); } template void pt(const T& first, const A&... rest) { std::cout << first; pt_rest(rest...); } static const ll INF=1e18+7; static const double PI=acos(-1); static const double EPS=1e-10; using v1=vector; using v2=vector; using v3=vector; int main(void) { cin.tie(nullptr); ios::sync_with_stdio(false); ll N;cin>>N; v1 a(N+1);for(ll i=1;i<=N;i++)cin>>a[i]; using mint=modint1000000007; vector dp(N+1); ll LIM=sqrt(N); vector> s(LIM+1,vector(LIM+1)); dp[1]=1; for(ll i=1;i<=N;i++){ for(ll j=1;j<=LIM;j++)dp[i]+=s[i%j][j]; if(a[i]>1 and i+1<=N)dp[i+1]+=dp[i]; if(a[i]<=LIM)s[i%a[i]][a[i]]+=dp[i]; else for(ll j=i+a[i];j<=N;j+=a[i])dp[j]+=dp[i]; } pt(dp[N]); }