After every odd number comes a even number
3(1)+1 = 4
3(3)+1 = 10
3(5)+1 = 16
3(7)+ 1 = 22
3(9)+1 = 28
In an expansion to a second digit
3(11)+1 = 34
3(13)+1 = 40
3(15)+1 = 46
3(17)+1 = 52
3(19)+ 1 = 58
Only the tens and one digits are needed to show all numbers when following the Collatz Conjecture get to one.
If both numbers in the ten and one digits are even, and prime (2) then it will divide once, before reaching an odd.
If both numbers in the ten and one digits are even, and not prime (2) it will be divided more than once before reaching an odd number
If the number in the ten digit is odd and the number in the one digit is even, it will divide into an odd number.
If the number in the ten digit is even and the number in the one digit is odd, it will become a even number