Hey, @XanderHenderson, @user21820, I will likely be taking a break from this site. Keep up the good work!

@amWhy Sorry to see you go, but do what you need. Good luck.

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[ SmokeDetector | MS ] Blacklisted website in answer: Counterfeit Coin Problem - 8 Coins by sakib abdul on math.SE

[ SmokeDetector | MS ] Blacklisted website in answer: Understanding weight spaces of weight module from its composition factors? by Callum Bennett on math.SE

This combinatorics question and that one are so similar (both use the same example and do not separate out the alphabet size as additional parameter $m$ in the question, and the answers do use $m$ but mostly fail to recognize the Stirling number relevance) that they could be merged. Presently I have flagged the older one as a duplicate (because it does not have the Stirling answer).

(I am biased though; the Stirling answeras of 2018-07-04 is mine,)

@ccorn I've voted to close the newer question as a duplicate of the older question. (1) You could repost your answer there (if it really is the same question, as it appears to be) and (2) closure generally does not lead to deletion (this is relevant).

The point of marking something as a duplicate is to provide a road-sign for the future.

Err... this link is the relevant link.