#include <bits/stdc++.h>
using namespace std;
const int N = 5000001;
int lp[N + 1], pcount[N + 1], cumm[N + 1];
vector<int> pr;
void sieve() {
  for (int i = 2; i <= N; i++) {
    if (lp[i] == 0) {
      lp[i] = i;
      pr.push_back(i);
    }
    for (int j = 0; j < (int)pr.size() && pr[j] <= lp[i] && i * pr[j] <= N; j++)
      lp[i * pr[j]] = pr[j];
  }
  for (int i = 2; i <= N; i++) {
    if (lp[i] == i) {
      pcount[i] = 1;
      cumm[i] = cumm[i - 1] + pcount[i];
    } else {
      pcount[i] = pcount[i / lp[i]] + 1;
      cumm[i] = cumm[i - 1] + pcount[i];
    }
  }
}
int main() {
  sieve();
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  int t;
  cin >> t;
  int a, b;
  while (t--) {
    cin >> a >> b;
    cout << (cumm[a] - cumm[b]) << '\n';
  }
  return 0;
}
