def sequence(x): count = 1 while x > 1: if(x%2 == 0): x=x/2 else: x=(x*3)+1 count+=1 return count print(sequence(13)) maxval, maxcount = 0,0 for x in range(1000000,100000,-1): currentSequence = sequence(x) if currentSequence > maxcount: maxcount = currentSequence maxval = x print(maxval,"with max sequence count of:",maxcount)