The Collatz Sequence
1. If the number is even, divide it in half
2. If the number is odd, multiply it by 3 then add 1
3. If the number reaches 1, stop; otherwise go to step 1
PROGRAMMING:
Prompt the user for an integer and display, for that integer, the Collatz Sequence. Continue prompting the user for a number to process until a negative number is entered, indicating the user wishes to quit the program.
Source Code:
inputStr = raw_input(“Input a number: “)
number = int(inputStr)
if number < 0:
print "You entered a negative number."
else:
print "Sequence for", number, "=>“, number,
while number > 1:
if number%2==0:
number = number / 2
else:
number = number*3+1
print number,
print
print “End”
Output:
