File:Collatz-graph-50-no27.svg
For a larger graph, see :Image:Collatz-graph-300.svg.
Created with Graphviz, with the help of this Python program:
dotfile = file('collatz-graph.dot', 'w')
limit = 50
def f(n):
while n % 2 == 0: # divide by 2 until it's odd
n /= 2
n = 3*n + 1
while n % 2 == 0:
n /= 2
return n
explored = set([1,27,31,41,47])
dotfile.write('digraph {\n')
for n in range(3, limit, 2): # odd numbers
while n not in explored:
dotfile.write(str(n) + ' -> ')
explored.add(n)
n = f(n)
dotfile.write(str(n) + ';\n')
dotfile.write('}\n')
