يمكن اعتبار المشكلة التي يثيرها هي مشكلة رياضية غير محلولة بعد وقد سميت باسم Lothar Collatz الذي اكتشفها عام 1937 م.

Summary

Directed graph showing the orbits of the numbers less than 30 (with the exception of 27 because it would make it too tall) under the Collatz map.

For a larger graph containing only odd numbers, see Image:Collatz-graph-300.svg.

Created with Graphviz, with the help of this Python program:

dotfile = file('collatz-graph.dot', 'w')

limit = 30

def f(n):
  if n % 2 == 0:
    return n / 2
  else:
    return 3*n + 1

explored = set([1,27]) # 27 has a long convergence, so skip it

dotfile.write('digraph {\n')

for n in range(2, limit):
  while n not in explored:
    dotfile.write(str(n) + ' -> ')
    explored.add(n)
    n = f(n)
  dotfile.write(str(n) + ';\n')

dotfile.write('}\n')

enSVG development

 

The SVG code is valid.

 

This diagram was created with Graphviz.

 

 This diagram uses embedded text that can be easily translated using a text editor.

Source code

dotfile = file('collatz-graph.dot', 'w')
 
 limit = 30
 
 def f(n):
   if n % 2 == 0:
     return n / 2
   else:
     return 3*n + 1
 
 explored = set([1,27]) # 27 has a long convergence, so skip it
 
 dotfile.write('digraph {\n')
 
 for n in range(2, limit):
   while n not in explored:
     dotfile.write(str(n) + ' -> ')
     explored.add(n)
     n = f(n)
   dotfile.write(str(n) + ';\n')
 
 dotfile.write('}\n')

Licensing

This work has been released into the public domain by its author, I, Keenan Pepper. This applies worldwide. In some countries this may not be legally possible; if so: I, Keenan Pepper grants anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.