File:Collatz-graph-all-30-no27.svg

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

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

 

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This diagram was created with Graphviz.

 

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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')

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.