Skip to main content
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
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
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 not deleted user 966209

For questions on introductory topics in number theory, such as divisibility, prime numbers, gcd and lcm, congruences, linear Diophantine equations, Fermat's and Wilson's theorems, the Chinese Remainder theorem, primitive roots, quadratic congruences, quadratic number fields, Pell's equations, and related topics.

1 vote
0 answers
74 views

Are there infinitely many $n\in\mathbb{N}$ which equals the sum of square of its smallest $k...

For $n\in\mathbb{N}$ , let $d_1<d_2<…<d_m$ be all divisors of $n$, where $d_1=1$, $d_m=n$, and $m=\tau(n)$ is the number of (positive) divisors of $n$ . Questions: There are two questions related with …
Tong Lingling's user avatar
9 votes
1 answer
198 views

Binomial coefficients sum $\sum_{k=1}^{n} \frac{1}{k}\binom{2k}{k}$ when $n>1$, $p=2n+1$ is ...

For a prime $p>3$, assume $n=\frac{p-1}{2}$. Question: Is it true that $\sum_{k=1}^{n} \frac{1}{k}\binom{2k}{k}\equiv0\text{(mod}$ $p)\,?$ A MATLAB program shows that there is no counterexample when $ …
Tong Lingling's user avatar