Bitwise NOTing any number x yields -(x + 1).

the if condition would drop all the 'centenarian (at least 100 years young)' !

just a reminder for those who missed the comment ...
this solution would only work if the term 'teen' is defined as 'any age lower than 20'
aka, would not pass test case such as [5,25,35,45,55,65,75,85,95,105]

thanks. I didn't know naming groups and groupdict()

It is not the triple quoting that allows comments! It is the VERBOSE flag.

I do not understand, what you are trying to say/ask.

sequence(n) (the function) does not produce a sequence, it produces the number at n-th position.
I.e. sequence: Z+ -> Z+

Look at examples once more, there is no 2 in the sequence. Not all numbers from 0 to 3 are present in the sequence.

Let me see if I'm getting this right, sequence(4) only includes numbers from 0 to 3, not 4 itself.

Then shouldn't sequence(4) return 7 instead of 9? Since 7 wouldn't form arithmic progression with any two numbers from: 0,1,2,3

5 is not in the sequence, as given in the example section. If it was, there would be a progression 1, 3, 5.

Thus, 0, 5, 10 is invalid.

I'm really lost here... how come sequence(5) should return 10??
Doesn't 0,5,10 form arithmic progression? Shouldn't it be 12 instead??

Also, is the given input part of the sequence or not?

I feel like this kata doesn't give enough examples, could have put in more examples, for example sequence(6), sequence(7).

I'd never thought of using reduce on this one! Neat!

I see, that's new to me :) Thank you

references for anyone interested:
https://docs.python.org/3/reference/lexical_analysis.html#string-literal-concatenation

https://stackoverflow.com/questions/8006551/how-to-split-long-regular-expression-rules-to-multiple-lines-in-python/8006611