ORIGINAL:

Links: the pictures are for those interested but short of the 10K threshold.

interesting how the deleted posts appear as https: and so on, while the undeleted appear as an underlined question title.

https://math.stackexchange.com/questions/3558299/is-this-on-symmetric-matrix-true

https://math.stackexchange.com/questions/3559339/does-this-hold-or-not

https://math.stackexchange.com/questions/3559389/proving-left-delta-1-dots-delta-8-right4-le4096-delta-1-cdot-dotsc

https://mathoverflow.net/questions/354446/any-counter-example-matrix

https://math.stackexchange.com/questions/3590234/on-matrix-with-det-0 The current version of the question is still open, as I write this. I now think this is a single OP crowdsourcing, well, something. There may or may not be a visible programming contest involved.

• Do you have a link to the post? – amWhy Feb 25 '20 at 21:22
• @amWhy I put those in. One young fellow answered the latest version, was interested about the repretitions, but lacks the 10 K to use the links. Some of them have been, I guess, briefly undeleted, edited, deleted again, so I took images from the editing queue rather than just the current version. – Will Jagy Feb 25 '20 at 21:28
• @WillJagy I noticed something similar relatively recently with $2$ other users. In both cases, the person has now at least twice, and I think 3 times, asked basically the same question, but deleted the posts basically as soon as they got some feedback & and an answer. Somewhat frustratingly, in both cases I was in the process of writing a somewhat lengthy comment when the text disappeared due to the OP deleting the question. I have pending moderator flags from Feb. $17$ and Feb. $21$ to check on & possibly deal with these users. I hope these flags are handled relatively soon. – John Omielan Feb 26 '20 at 2:30
• @JohnOmielan thanks. I did flag on the deleted posts, I don't know whether anything really happens with those. One quick thing is just to "favorite" a question when suspecting imminent self-deletion. Later I copied the url's to a text file, eventually made the images when there was a sub 10k user involved and wondering what was going on. – Will Jagy Feb 26 '20 at 2:37
• You'll have noticed, Will, that I left comments on several of those questions, and wondered aloud whether/why someone was posting (essentially) the same question repeatedly. But I couldn't find the deleted versions, so I let it go. You've done well to find them. The poster definitely needs a talking to from the moderators. – Gerry Myerson Feb 26 '20 at 5:54
• @GerryMyerson right, when I saw your comments i began to "favorite" overly similar questions. I got better at it, the thing to do is favorite the question before anything else, once there seems a pattern of deletion. ...I still don't know what it is about. There are many, many programming contests worldwide, but there are also teachers who give individual students, or classes, such projects. – Will Jagy Feb 26 '20 at 18:27
• Wouldn't flagging one of the questions for moderator attention do the trick? They can usually figure out all the sockpuppet accounts used, and they can see deleted stuff that we cannot see if we don't have a link. – user21820 Feb 28 '20 at 15:21
• @user21820 I did that. I would not necessarily be informed if they did anything. Meanwhile, this post shows the poor behavior to a wider audience. – Will Jagy Feb 28 '20 at 16:28
• Ah yes indeed. Thanks for bringing it to everyone's attention! =) – user21820 Feb 28 '20 at 16:30
• @WillJagy It seems that this question math.stackexchange.com/q/3565024/631742 could be by the same person: Indeed the question style is very similar and it was asked by an account created today – Maximilian Janisch Mar 1 '20 at 15:08
• @MaximilianJanisch you may have a point. There is the same entitlement, the OP admits no responsibilities and keeps bugging anyone answering for more work on their part – Will Jagy Mar 1 '20 at 15:29
• If I had to guess, some of these MIGHT be questions from a take-home exam. – rocksNwaves Mar 2 '20 at 15:27
• I would be very encouraged to have a moderator on this site answer, or comment, even if only to the effect, "The mod team is dealing with this." – amWhy Mar 2 '20 at 15:32
• Can't see the questions but from images it looks like PSQs which should be ideally just closed for lack of context if our process is right, so it shouldn't be too much of a problem? I mean, in particular case a moderator can do something about it, but if it happens by other users, this is how it should end up anyway... – Sil Mar 4 '20 at 7:52
• @MaximilianJanisch I added the link. Certainly the attitude of the person asking is the same, and it was self-deleted an hour ago. – Will Jagy Mar 22 '20 at 16:44