Question

The Syracuse sequence is generated by starting with a natural number and repeatedly applying the following function until reaching 1: ???(?) = { ?/2 if x is even { 3? + 1 if x is odd

For example, the Syracuse sequence starting with 5 is: 5, 16, 8, 4, 2, 1. It is an open question in mathematics whether this sequence will always go to 1 for every possible starting value. Write a function in Python (called syracuse) that gets a starting value as input and returns the Syracuse sequence in a list for that starting value.

Answer 1

def syracuse(x):
    lst = []
    while(x!=1):
        lst.append(x)
        if(x%2==0):
            x = x // 2
        else:
            x = 3*x + 1
    lst.append(x)
    return lst

#Testing
print(syracuse(5))

[5, 16, 8, 4, 2, 1]