C/D This was originally closed as a dupe of this and this but was reopened after the OP made a minor fix. It should be reclosed and deleted - we already have hundreds of questions on this and there is nothing novel here.
Alright, I saw this problem on wikipedia's list of unsolved problems and was hoping to get some more insights...
Are there any composite c satisfying $2^{c − 1} ≡ 1 \mod c^2$
@XanderHenderson Perhaps it is time to think about enforcing stricter requirements on SV = solution verification questions since users are exploiting the lack of such to reopen dupes of FAQs, e.g. see Jose's comment here
I do not at all agree with rschwieb's statement that "the way we get feedback for solutions is to post them as a solution, and then people have at them". People who have a very weak foundation in mathematics should not be dumping their so-called 'proof attempt' of any mathematical problem onto an...
I think the criteria I laid out in that post is in line with your "nothing novel" point.
@user21820HATESSMOKING-HATS Yes, in fact I upvoted your answer long ago. It seems we are in agreement on most of the major issues regarding verification questions. It appears that many users don't realize how much these matters negatively impact searching since most users rarely spend significant effort searching (for dupes or for answers to their own questions).
@BillDubuque Personally, I would love to. However, I don't think that there is a very strong community consensus around that that tag (a tag which, for the record, I would be happy to burninate). solution-verification is, at best, a controversial tag.
Does there exist $\ N\in\mathbb{N}\ $ such that every natural number $\ n\geq N\ $
can be written as the sum of square numbers, where each square number
is allowed to be used at most once in the sum ? Or does no such $\ N\ $ exist?
For example, the sum of square numbers cannot equal $\ 28,\ $ s...
here is my writeup (in v.0.75): https://bytes.usc.edu/~saty/math/Collatz/
I'd love your thoughts on it. Thanks!
Alright, I saw this problem on wikipedia's list of unsolved problems and was hoping to get some more insights...
Are there any composite c satisfying $2^{c − 1} ≡ 1 \mod c^2$
