I really think that "popular" questions are treated with inappropriate hostility here.
Do I think that "What is the rule for constructing the sequence $3,4,6,10$?" is a mathematically interesting question? No, of course not, because I already have a lot mathematical experience.
Do I agree that trending youtube videos on the sum of all natural numbersgenerate very naive questions here? Sure, I do, because I know Banach limits, Zeta functions, renormalization, etc.
But this is because I already know a lot about mathematics. Some questions about university mathematics seem not any less naive to me, but many people who will jump on closing a "guess the sequence"-question will approve the other question because they can empathize with it.
Now, for the example that motivated this thread: Number-guessing: https://math.stackexchange.com/questions/682652/complex-math-question
The question is clearly a "guess the rule of the sequence 3,4,6,10 - question". It was originally tagged "mathematical physics, complex analysis, contest- math".
I do not find any of these tags appropriate, but on the one hand, the person who edited them not only left in "complex analysis", but added in "algorithms" which is not appropriate, either, and on the other hand, this context clearly tells us that the asker has little background in mathematics, wanted to label the question "difficult" and found "complex-*" tags instead.
The questions was "put on hold as unclear what you're asking", but it is perfectly clear what is being asked. The comments asking for "are you talking about a sequence where $a_n =$ function of $n$" ignore that the OP does not have to know functions or sequences to ask or understand this question.
A proper answer to this question would be: Link to the Encyclopedia of Integer Sequence explaining in what sense it is appropriate to use, explain how the formula could be found by hand for this particular sequence.
Ideally, we would have a detailled answer for the common types of question (recognize the differences in this case, or see that repeated differences are 0, look at the binary representation, ...).
If people think that this is a good place to post "guess the number"-sequences as riddles, one can just explain to them that they should state that they know the answer, but otherwise, there is no harm at all.
I am even more discontent with the angry closures of the $1+2+3+\dots $- threads. This video generated interest and was a perfect opportunity to write very different informative answers on different ways of assigning values to divergent sums and the merits and flaws of the video. Sure, duplicates should have been closed and redirected to the thread with the model answers. But they should have been closed gracefully with enjoyment of the enthusiasm of the askers.
And I have seen no excellent comprehensive answers that would merit a link for people stumped by the video seeking background information. Since the first questions did not mention the video and the later questions were closed quickly and with hostile comments, it was impossible to actually write a good answer about the implied question "Is this video serious? How can this work?". "Because zeta functions and you lack the math background to understand it, so go away." is really not a very good answer.
So, I am strongly in favour of treating people with little background in a friendly way and answer their questions either directly or by linking to a generic question with excellent answers, especially if it is obvious that they came here to ask a question out of curiosity. I am posting this here to hear your opinions on these issues.