similar to the pathway of Gauss? Wow :)

Thanks for the feedback. Actually, I'm not english mother tongue; so, maybe, the description can be improved, it can be fair: have you any specific advice?
Apart from that, more than 130 people in this community have solved this (relatively) easy kata without giving to me this feeling. In my opinion, this is not the point.

In this community, as we gain experience with several katas we feel the need to step up our code skills. I looked at your solution and, frankly speaking, I am pretty sure you don't really understood the truly essence of this kata: that is the point. I hope this kata(and his description), at least, helped you think.

This is exactly the same feeling I experienced the first time I solved this kind of exercise here at CodeWars.
It also one of the reason why I decided to write this basic kata.
Now on, I'm pretty sure that you will take advantage of the work with this kata with the others katas of this kind.

Chris, first of all, thank you for the feedback.
Actually, I do not really think that adding an extra line, with a story, to the sentence 'the problem of adding up all the whole numbers from 1 through a given number n.' can influence the ability to solve the problem.
Moreover, in the field of science and maths this is a quite famous anecdote; moreover, it is also an hint, since this is where all the studies for a more efficient solution come from. I can understand that not everybody have this academic background or the willingness to spend time on the internet in order to discover all the details of the story.
In fact, you are still able to solve the problem even if you can't appreciate all the historical details or if it not works as an hint for you.

Thanks for the feedback.
I think that, if your code was not able to pass the final submission, it was because of an error in your code.
In fact, nothing has changed here.
So, please, because you have already passed the kata, look at all the test cases in the 'official solution' and double check your solution. In case of further investigations are needed, post here your code (marking as having spoiler content).

Thanks for the feedback.
Sure, you are right. As explained in the description, here, my choice was to encourage people to discover such a formula and to apply it but, not to enforce its usage. At this introductory level, even a work on loop's optimization it's fine.
Of course, when I wrote that solving this kata with a general formula can be useful as a training for more complex katas, it's up to the single code-warrior to think what is the best strategy for him/her.
Moreover, adding a specific test case now, I will risk to invalidate some of the solutions.

As many others, it was the first time I faced a kata like that. Even if I feel that it open the door to a set of problems where I have no knowledge, I enjoyed it.

Thank you very much. It was my first kata for the community. Another little step done along the pathway :)

Ok, I have updated it.
Thanks!

As already written, and it's also my opinion, this kata should benefit from a bit of work on its own introduction and on its own test cases; that is, the already mentioned difference between a challenging kata and a cryptic kata; apart from these details, it's a great kata about the closure, by the way.

@kgashok - javascript translation kumited! :)

javascript translation kumited!

ok, thanks for the feedback and for the links :)

They are similar for sure.

I argue that, maybe, they can be seen from different perspectives and, each one, has its own peculiarities.