Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Favorites infavorites:mine
infavorites:1234
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with Search options user 1731

A puzzle strongly related to mathematical facts and objects, or whose solution needs serious mathematical arguments. General mathematics questions are off-topic but can be asked on Mathematics Stack Exchange.

7
votes
Concatenation is the "most efficient" among the allowed operations, which is exmplified by this observation: If $x$ is a nonzero rational number obtained according to the rules using the $k$ digits $d …
answered Jul 6 '14 by Hagen von Eitzen
3
votes
They try to prove Note that and are obvious reasons to fail. The proof can be elaborated like this:
answered Jan 15 '17 by Hagen von Eitzen