Currently, I have 9*9*2*8 as there are 9 ways for the 1st and 3rd digit, 2 ways for the second digit, and 8 ways for the last one. This is incorrect and I do not know why so it would be nice if you could explain why im incorrect

9 possibilities for the first and third digits, and if the second digit is 2, there are 6 possibilities for the last digit, and if the second digit is 4, there are 2 possibilities for the last digit.