func_code_string: #include <bits/stdc++.h>   using namespace std;   using ll = long long;   using pii = pair<int, int>;   using pil = pair<int, ll>;   using pli = pair<ll, int>;   using pll = pair<ll, ll>;   template <typename T>   bool chmax(T &x, const T &y) {     return (x < y) ? (x = y, true) : false;   }   template <typename T>   bool chmin(T &x, const T &y) {     return (x > y) ? (x = y, true) : false;   }   template <typename T>   int flg(T x, int i) {     return (x >> i) & 1;   }   template <typename T>   void print(const vector<T> &v, T x = 0) {     int n = v.size();     for (int i = 0; i < n; i++) cout << v[i] + x << (i == n - 1 ?   n  :    );   }   template <typename T>   void printn(const vector<T> &v, T x = 0) {     int n = v.size();     for (int i = 0; i < n; i++) cout << v[i] + x <<   n ;   }   template <typename T>   int lb(const vector<T> &v, T x) {     return lower_bound(begin(v), end(v), x) - begin(v);   }   template <typename T>   int ub(const vector<T> &v, T x) {     return upper_bound(begin(v), end(v), x) - begin(v);   }   template <typename T>   void rearrange(vector<T> &v) {     sort(begin(v), end(v));     v.erase(unique(begin(v), end(v)), end(v));   }   template <typename T>   vector<int> id_sort(const vector<T> &v, bool greater = false) {     int n = v.size();     vector<int> ret(n);     iota(begin(ret), end(ret), 0);     sort(begin(ret), end(ret),          [&](int i, int j) { return greater ? v[i] > v[j] : v[i] < v[j]; });     return ret;   }   struct io_setup {     io_setup() {       ios_base::sync_with_stdio(false);       cin.tie(NULL);       cout << fixed << setprecision(15);     }   } io_setup;   const int inf = (1 << 30) - 1;   const ll INF = (1LL << 60) - 1;   const int MOD = 1000000007;   template <int mod>   struct Mod_Int {     int x;     Mod_Int() : x(0) {}     Mod_Int(long long y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}     static int get_mod() { return mod; }     Mod_Int &operator+=(const Mod_Int &p) {       if ((x += p.x) >= mod) x -= mod;       return *this;     }     Mod_Int &operator-=(const Mod_Int &p) {       if ((x += mod - p.x) >= mod) x -= mod;       return *this;     }     Mod_Int &operator*=(const Mod_Int &p) {       x = (int)(1LL * x * p.x % mod);       return *this;     }     Mod_Int &operator/=(const Mod_Int &p) {       *this *= p.inverse();       return *this;     }     Mod_Int &operator++() { return *this += Mod_Int(1); }     Mod_Int operator++(int) {       Mod_Int tmp = *this;       ++*this;       return tmp;     }     Mod_Int &operator--() { return *this -= Mod_Int(1); }     Mod_Int operator--(int) {       Mod_Int tmp = *this;       --*this;       return tmp;     }     Mod_Int operator-() const { return Mod_Int(-x); }     Mod_Int operator+(const Mod_Int &p) const { return Mod_Int(*this) += p; }     Mod_Int operator-(const Mod_Int &p) const { return Mod_Int(*this) -= p; }     Mod_Int operator*(const Mod_Int &p) const { return Mod_Int(*this) *= p; }     Mod_Int operator/(const Mod_Int &p) const { return Mod_Int(*this) /= p; }     bool operator==(const Mod_Int &p) const { return x == p.x; }     bool operator!=(const Mod_Int &p) const { return x != p.x; }     Mod_Int inverse() const {       assert(*this != Mod_Int(0));       return pow(mod - 2);     }     Mod_Int pow(long long k) const {       Mod_Int now = *this, ret = 1;       for (; k > 0; k >>= 1, now *= now) {         if (k & 1) ret *= now;       }       return ret;     }     friend ostream &operator<<(ostream &os, const Mod_Int &p) {       return os << p.x;     }     friend istream &operator>>(istream &is, Mod_Int &p) {       long long a;       is >> a;       p = Mod_Int<mod>(a);       return is;     }   };   using mint = Mod_Int<MOD>;   int main() {     int N;     cin >> N;     vector<int> a(N);     for (int i = 0; i < N; i++) cin >> a[i];     int M = 100000;     vector<vector<int>> ds(M + 1);     vector<ll> c(M + 1);     iota(c.begin(), c.end(), 0);     for (int i = 1; i <= M; i++) {       ds[i].emplace_back(i);       for (int j = 2 * i; j <= M; j += i) {         c[j] -= c[i];         ds[j].emplace_back(i);       }     }     mint ans = 0;     vector<ll> cnt(M + 1, 0);     vector<bool> used(M + 1, false);     for (int i = 1; i <= N; i++) {       mint tmp = 0;       for (int j = i - 1; j < N; j += i) {         for (auto &e : ds[a[j]]) {           used[e] = true;           cnt[e]++;         }       }       for (int j = i - 1; j < N; j += i) {         for (auto &e : ds[a[j]]) {           if (used[e]) {             used[e] = false;             tmp += c[e] * cnt[e] * cnt[e];           }           cnt[e]--;         }       }       ans += tmp * c[i];     }     cout << ans <<   n ;   }   