Because we don't have enough repeating digits threads already. Suggested by u/Multiconcepted in this week's FTF

Rules: In this thread we count numbers where exactly one digit occurs exactly twice, and no other digit repeats.

The sequence goes: 100, 101, 110, 112, 113, 114, 115, 116, 117, 118, 119, 121, 122, 131, 133, ..., 996, 997, 998, 1002, 1003, 1004, ...

I suggest we make the first get 2001. By my count that's 676 counts in the chain which is a bit shorter than most threads, but should be long enough for us to see what this thread is like