I have asked this question yesterday: On the sum of digits of $n^k$ and it doesn't seem likely to receive a definitive answer anytime soon.

As TonyK pointed out in his answer the (seemingly simpler) problem of whether $\lim\limits_{n\to\infty}S(2^n)=\infty$ (which is actually a prerequisite for my question) is also not likely to have been proved, is it ok to open a new question on this problem (possibly a reference request to find works on this problem and related ones) or would that be too similar and counted as a duplicate?

Normally I would just edit the question, but it was already reduced from a search for a generic $n^k$ to the specific case of $n=2$

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    $\begingroup$ I for one would not object to such a derived question, more so since TonyK's post is not really providing an answer but definitely a valuable contribution to the site. $\endgroup$
    – Lord_Farin
    Jan 15, 2015 at 20:13
  • $\begingroup$ It won't be necessary in this case, since a user provided a link answering to the specific $n=2$ case (it had already been asked before, but somehow I missed it when searching for duplicates before asking), but if I ever find myself in the same situation I'll go ahead and ask the second question! $\endgroup$ Jan 15, 2015 at 20:45

1 Answer 1


As Lord_Farin says, this is completely acceptable. As long as the derived, specific question is significantly different from the original question (if it is much easier, then I would say that counts as significantly different), it can be posted as a new question.

In general, any question that is derived from or related to a previous question in some way is acceptable as long as it differs significantly.

But in this and other cases, make sure to include a link to the original question so that people can see that the two questions are related.

  • $\begingroup$ You might also put a link in the first question to the derived question - or questions $\endgroup$
    – Joffan
    Jan 28, 2015 at 18:58
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    $\begingroup$ @Joffan You can, although the software will automatically list each question as "Linked" from the other, even if the you only explicitly post a link one way. $\endgroup$ Jan 29, 2015 at 2:11
  • $\begingroup$ Handy to know, thanks. $\endgroup$
    – Joffan
    Jan 29, 2015 at 2:46

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