I need to make a password in php and javascript (with html) so that if the user wants the password to be 6 digits long, then the password is y0z0z2z4z6y2z0z2z4z6y4z0z2z4z6y6z0z2z4z6… If the password is 4 digits long, then the password is y0z0z2z4y2z0z2z4y4z0z2z4.

THESE ARE NOT RANDOM NUMBERS. There is a pattern within those passwords. Can someone please send me their suggestion on how this could be done?

This is a completely incomprehensible question that makes no sense and you are probably wanting something very bad and insecure.