Username data for naturally taken usernames (not counting username changes):
Last:
X: ?
XX: @66
2num: @98
2char/letter: @dt (maybe)
3char/letter: ? (Maybe @/ao3, not @‘ing cause unsure)
bX: @bz
cX: @cz
Second lasts:
X: ?
XX: @33 (@/55 had a username change and is now @-_ ).
2num: unsure, possibly @97
2char/letter: maybe @ds
3char/letter: ?
bX: @bx (lol)
cX: @cx (lol)
Data from: me, @up, the api and random posts
There are lots more “impossible” usernames with the name limit change…
Part 1: 1char.
Part 2: Accounts with “.”
Part 3: 2num.
Part 4: Miscellaneous 2char.
Part 5: 3char.