SPOILERS:
I made the door sequence in a haste during the jam and the lock gives in to any sequence which makes a total of 20. It comes from 1973 which was the year Enter the Dragon hit the theaters. It was a placeholder at the time. I meant to go back to that part and think of something more clever, since now you can't figure it out before playing the game through once. Now it is just a game of chance which some people have solved by sheer luck.
Dude, now that you mention it, I was going to try 1973! It's the date mentioned in the talk with Lizzie, isn't it? Since it was the only four digit number I saw all playthrough, I wrote it down to try it later. But then I thought it made no sense that an inner joke between the main characters would have any bearings in the choice of numeric code for the whole apartment building... I wound up scrapping that choice and just guessed there was no way to get through the door.
Well, in any case, thanks for relieving me of that uncertainty. It was killing me XD
