#include <bits/stdc++.h>

#ifdef DEBUG
#include <Mylib/Debug/debug.cpp>
#else
#define dump(...) ((void)0)
#endif

template <typename T, typename U>
bool chmin(T &a, const U &b){
  return (a > b ? a = b, true : false);
}

template <typename T, typename U>
bool chmax(T &a, const U &b){
  return (a < b ? a = b, true : false);
}

template <typename T, size_t N, typename U>
void fill_array(T (&a)[N], const U &v){
  std::fill((U*)a, (U*)(a + N), v);
}

template <typename T, size_t N, size_t I = N>
auto make_vector(const std::array<int, N> &a, T value = T()){
  static_assert(I >= 1);
  static_assert(N >= 1);
  if constexpr (I == 1){
    return std::vector<T>(a[N - I], value);
  }else{
    return std::vector(a[N - I], make_vector<T, N, I - 1>(a, value));
  }
}

template <typename T>
std::ostream& operator<<(std::ostream &s, const std::vector<T> &a){
  for(auto it = a.begin(); it != a.end(); ++it){
    if(it != a.begin()) s << " ";
    s << *it;
  }
  return s;
}

template <typename T>
std::istream& operator>>(std::istream &s, std::vector<T> &a){
  for(auto &x : a) s >> x;
  return s;
}

namespace haar_lib {
  template <typename T, typename Add = std::plus<T>, typename Minus = std::minus<T>>
  class cumulative_sum_1d {
    std::vector<T> data;
    const int N;
    const Add add;
    const Minus minus;
    bool is_built = false;

  public:
    cumulative_sum_1d(const std::vector<T> &a, const T &e = 0, const Add &add = Add(), const Minus &minus = Minus()):
      N(a.size()), add(add), minus(minus)
    {
      data.assign(N + 1, e);
      for(int i = 0; i < N; ++i) data[i + 1] = a[i];
    }

    cumulative_sum_1d(int N, const T &e = 0, const Add &add = Add(), const Minus &minus = Minus()):
      N(N), add(add), minus(minus)
    {
      data.assign(N + 1, e);
    }

    auto& update(int i, const T &val){
      assert(not is_built);
      data[i + 1] = add(data[i + 1], val);
      return *this;
    }

    auto& build(){
      assert(not is_built);
      for(int i = 0; i < N; ++i) data[i + 1] = add(data[i + 1], data[i]);
      is_built = true;
      return *this;
    }

    /**
     * @attention [i, j)
     */
    T get(int i, int j) const {
      assert(is_built);
      return minus(data[j], data[i]);
    }
  };
}



namespace haar_lib {}

namespace solver {
  using namespace haar_lib;

  constexpr int m1000000007 = 1000000007;
  constexpr int m998244353 = 998244353;

  void init(){
    std::cin.tie(0);
    std::ios::sync_with_stdio(false);
    std::cout << std::fixed << std::setprecision(12);
    std::cerr << std::fixed << std::setprecision(12);
    std::cin.exceptions(std::ios_base::failbit);
  }

  constexpr int MAX = 20;

  void solve(){
    int N; std::cin >> N;
    std::vector<int64_t> A(N); std::cin >> A;

    std::vector<int> count(MAX + 1);
    for(auto x : A) count[x] += 1;
    cumulative_sum_1d cs(count);
    cs.build();

    int64_t sum = std::accumulate(A.begin(), A.end(), 0LL);

    int64_t ans = 0;
    dump(cs.get(1, MAX + 1));
    for(int i = 1; i <= MAX; ++i){
      if(count[i] == 0) continue;
      ans += sum * count[i];
      dump(ans);
      for(int j = i; j <= MAX; j += i){
        ans -= (int64_t)i * cs.get(j, MAX + 1) * count[i];
      }
      dump(ans);
    }

    std::cout << ans << "\n";
  }
}

int main(){
  solver::init();
  while(true){
    try{
      solver::solve();
    }catch(const std::istream::failure &e){
      break;
    }
  }
  return 0;
}