OP solved the kata

oh my.
I feel so sad with my solution when I see this.

this is probably the cleanest solution

Sadly, the tests don't give any gratification for finding a way.

They only really give you reward for complying with the reference solution.

Which reads "1001" as ". ." rather than ".." which seems way more fitting the description of 2/3 part of series.

I would be very careful with += and =+
syntax is short but can introduce unexpected behaviour

you need to specify radix to stay on the safe side

this is not best solution.
it does look clean but performance wise it's not nice.

You definitely learn thing or two in this kata.

same here.
I do find descriptions of SQL tasks bit cryptic.

Works fine on my machine, could you explain the issue a bit further?

🤔 return without value
bit to much of magic here for my taste

No need of kmeans.