Thomas Browning's user avatar
Thomas Browning's user avatar
Thomas Browning's user avatar
Thomas Browning
  • Member for 7 years, 7 months
  • Last seen this week
  • Berkeley, CA, United States
53 votes
3 answers
1k views

Bijection $f\colon\mathbb{N}\to\mathbb{N}$ with $f(0)=0$ and $|f(n)-f(n-1)|=n$

28 votes
1 answer
797 views

Is $\sum_{a=0}^m\sum_{b=0}^n\cos(abx)$ always positive?

24 votes
0 answers
547 views

Abstract proof that $\lvert H^2(G,A)\rvert$ counts group extensions.

23 votes
0 answers
619 views

Maximal subgroups that force solvability.

23 votes
1 answer
752 views

Probability of random sphere lying inside the unit ball

14 votes
7 answers
1k views

If $2^{2k}-x^2\bigm|2^{2k}-1$ then $x=1$ [duplicate]

14 votes
1 answer
368 views

Is a product of $p$-subgroups still a $p$-subgroup?

13 votes
1 answer
474 views

Fundamental group of punctured simply connected subset of $\mathbb{R}^2$

10 votes
4 answers
711 views

If $y^2-x^2\bigm|2^ky-1$ and $2^k-1\bigm|y-1$ then $y=2^k$ and $x=1$

10 votes
1 answer
358 views

Is there a prime of the form 711...117?

10 votes
2 answers
582 views

When is the compact-open topology locally compact?

9 votes
1 answer
148 views

Is $S_6$ the derived subgroup of some group?

8 votes
1 answer
242 views

Growth of powers of symmetric subsets in a finite group

7 votes
3 answers
181 views

If $p^k|n!$ then $p!^k|n!$

5 votes
1 answer
211 views

Kernel of $G\ast H\to G\times H$ is free

5 votes
1 answer
262 views

For odd primes $p$, are finite groups with self-normalizing Sylow $p$-subgroups solvable?

5 votes
0 answers
112 views

Criterion for $PSL(2,q)$

5 votes
3 answers
378 views

Combinatorial Proof of Stirling Number Inequality

5 votes
2 answers
264 views

Group with fewer than $p^2$ Sylow $p$-subgroups

5 votes
1 answer
113 views

When are homomorphisms automatically continuous?

4 votes
3 answers
365 views

The Diophantine equation $x^5-2y^2=1$

4 votes
1 answer
229 views

Parametrization of the curve $x^{x^y}=y$

4 votes
0 answers
111 views

Pattern in Number of Conjugacy Classes of p-groups

4 votes
0 answers
571 views

Conjugacy classes of a quotient group

4 votes
0 answers
628 views

Function where some derivative vanishes at every point.

3 votes
1 answer
863 views

Free subgroups of $PSL(2,\mathbb{Z})$ of index 6

3 votes
1 answer
258 views

Quotient of Riemann surface by properly discontinuous group action

3 votes
0 answers
195 views

Loops through zero in Arnold's proof of the insolvability of the quintic

3 votes
2 answers
115 views

Is there a tessellation with no corners?

3 votes
1 answer
121 views

Group Law on Specific Elliptic Curve