try to be nice akar-0, goddamn, we are all starting somewhere

I had assumed that some of the tests would involve very large numbers that would render a brute force approach futile and so I spent a fair amount of time researching Faulhaber's Formula and algorithms for calculation of Bernoulli numbers. While taking a pause I tried the simple for loop approach on a lark and was shocked to see it pass all the tests.

It's always satisfying to see ones points go up but I think the tests need to require a more optimized solution in order for this to be 4 kyu.

very minor but, I don't think you should be using the k=1 substitution in the example, it felt quite dumb when I realized I was missing the k next to the 2 power

@akar-0 gotta push someone to show me the north :-)
have a great day otherwise

@Blind4Basics if you have a resource on that then fell free to link it.

and about the how: read more about python operations for sets (and/or "comprehensions", if needed)

Use a spoiler flag.

ty king

thank you FArekkusu