[ SmokeDetector | MS ] Bad keyword in link text in body, potentially bad keyword in body (70): How many variation are there in this sequence of numbers: 1, 2,3,4 : 1,2,3,4 Minus and plus numbers ✏️ by Edward Small on math.SE

Repfarmers trying to protect their ego-point gravy train.

@RRL All deleted now, I think.

U1 good answers, not duplicated since only a particular case of other topic

ah actually, it's indeed equivalent

then it's not an undelete candidate, sorry; but at least one answer needs merging

@JyrkiLahtonen I wonder how that could become a “Hot Network Question” ...

@JyrkiLahtonen It can be deleted now. Perhaps that it should, since it has a reopen vote.

[ SmokeDetector | MS ] Bad keyword in link text in body, potentially bad keyword in body (70): How many variation are there in this sequence of numbers: 1, 2,3,4 : 1,2,3,4 Minus and plus numbers ✏️ by Edward Small on math.SE

Thanks @JoséCarlosSantos.

D1, D2, D3.

D4, D5, D6.

D7, D8, D9.

D10, D11, D12.

C1, C2, C3.

C4, C5, C6.

@user21820 With respect to D2: It is a duplicate, but is it really a bad question so that it should be deleted? OP explains what they try to calculate and how and there is an attempt. Even if that attempt is wrong, the question looks better to me than many others on this site.

@MartinR It's borderline to me. Definitely not as bad as many others, but I got the subjective feeling that the asker didn't put in effort into finding out how contour integration worked and just dumped the question to Math SE. I mean, why not ask the answerers in the linked question that the asker admits has evaluation of that integral?

The key question I use (which I also ask my students) is: What exactly is the first point (of some solution/proof) that you do not understand? One can't just say "I don't understand everything"...

And after that, exactly where in robjohn's answer do you get lost?

That's my view, anyway.