Usage drand48:
      10  3.46410162
     100  3.11085508
    1000  3.12347524
   10000  3.15335577
  100000  3.14122349
 1000000  3.14092649
10000000  3.14209456
       Pi 3.14159265358979

Usage ChaCha20:
      10  3.46410162
     100  3.08606700
    1000  3.11588476
   10000  3.14606477
  100000  3.14461263
 1000000  3.14453748
10000000  3.14269499
       Pi 3.14159265358979

Usage /dev/urandom:
      10  3.16227766
     100  3.13625024
    1000  3.24727816
   10000  3.13959750
  100000  3.14238646
 1000000  3.14247180
10000000  3.14023908
       Pi 3.14159265358979