Didn't mean to say that it's bad, but look yourself: here was created array, mapped to adjust indexes, and only then mapped to multiply to reduce. It seems overhead for me to iterate 2 times array of required length just to count numbers inside.
I'm upset because people are more likely to vote if they see shorter solution.
export const sumCubes = (n: number): number => Array.from({length: n}, (_,i)=> i+1).reduce((a, b)=> a+b**3, 0)
here is same solution but with properly used reduce and no map, you can take it

I don't know why it's concidered as a good practice, because I would have no clue what's going on in this ZAMES(mess).

Perfect example of power of ES6

Why people upwote solution as best practice where you have single character variable naming?

You MUST return null | number

Fucjing awesome.

The best.

POSOSI HUY. I bet you from Ukrain.

So bad