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ArtW
  • Member for 7 years, 6 months
  • Last seen this week
  • Antwerp, Belgium
10 votes
Accepted

Prove or disprove that $2^n$ divides $T_{2^n}$ for $n > 2$.

10 votes
Accepted

What is this manifold?

8 votes
Accepted

Find the value of $(a+b-c)/(a+b+c)$

7 votes
Accepted

A quotient of a polynomial ring

7 votes
Accepted

The Mordell equation $x^2 + 11 = y^3$.

6 votes
Accepted

Is there a univariate rational polynomial which represents only squares in $\mathbb{R}$ and $\mathbb{Q}_2$, but not all other $\mathbb{Q}_p$?

6 votes

Galois Group of splitting field of $ X^5 - 4X + 6 $ over $\mathbb{Q}$

6 votes
Accepted

Degree of Field Extension $\mathbb{Q}(\sqrt[4]{2}):\mathbb{Q}(\sqrt{2})$

5 votes

$\mathbb{Z}_p$ is an Integral Domain

5 votes
Accepted

$f(x) = x^6, g(x) = x^{10}$ endomorphisms $\implies G$ is abelian

4 votes
Accepted

Proving the ratio of curvature and torsion is constant.

4 votes
Accepted

Show that $\sum_{r=1}^n r^4=\frac{3n^2+3n-1}5\sum_{r=1}^n r^2$

4 votes
Accepted

Prove that $p$ does not divide $a^2+b^2$

3 votes
Accepted

Triangle-free graph where every pair of nonadjacent vertices has exactly two common neighbors

3 votes
Accepted

Cardinal of quotient rings of gaussian integers.

3 votes
Accepted

Coloring classes of $\{1,2,3,\dots,n\}$

3 votes
Accepted

For a surjective function $f: A \rightarrow A$, if there exist $n$ such that $\ker f^n = \ker f^{n+1} = \dots$ Is f injective?

2 votes

Graph embedding in space: always possible?

2 votes

Prove concurrency in a triangle

2 votes
Accepted

Number of ways to partition a set with $2n$ elements into unordered pairs

2 votes
Accepted

Prove that the product is not an integer

2 votes
Accepted

$\mathbb{Z}[\sqrt{-5}]$ satisfies the descending chain condition of divisors

2 votes

Show that $\sigma_0(N) = \frac{1}{N}\sum_{d|N} \sum_{l=1}^d \mathrm{gcd}(d,l)$

2 votes

Proof concerning regular space: there exist a closed set contained in any open set containing $x$

2 votes

$\sum_{1\le k\le n,~k\mathrm{~odd}}k\binom{n}{k}=n\cdot2^{n-2}$ for $n>1$

2 votes
Accepted

Graph with $|G| = 6$, $G$ and its complement $G'$ contains at least two triangles together

2 votes

Help ending a proof using binomial theorem: $\sum_{k=0}^n {n \choose k}\cdot\frac{(-1)^k}{k+1} = \frac{1}{n+1}$

1 vote

Prove $a_{n+2}=3a_n+2\sqrt{2a_n^2+2a_{n+1}^2}$ is an integer

1 vote

For all positive integer $n$ prove the equality: $\sum_{k=0}^{n-1}\frac{\binom{n-1}{k}^2}{k+1}=\frac{\binom{2n}{n}}{2n}$

1 vote
Accepted

Mobius transformation on the open upper half plane