Nathan Portland
  • Member for 10 years, 4 months
  • Last seen this week
3 answers
20 votes
3k views
14 bookmarks
$A_6 \simeq \mathrm{PSL}_2(\mathbb{F}_9) $ only simple group of order 360
2 answers
12 votes
471 views
2 bookmarks
Embeddings of finite groups into $\mathrm{GL}_n(\mathbb{Z})$
1 answers
11 votes
2k views
1 bookmarks
Eigenvalues of doubly stochastic matrices
1 answers
10 votes
256 views
1 bookmarks
$\mathcal{O}(n,\mathbb R)$ spans $\mathcal{M}(n,\mathbb R)$
1 answers
8 votes
332 views
5 bookmarks
Number of factors of $2^{p_1\cdots p_n}+1$
4 answers
8 votes
4k views
4 bookmarks
Algebraically closed field with characteristics $0$ versus $\mathbb{C}$
1 answers
7 votes
107 views
2 bookmarks
Matrix restoring (modulo n)
2 answers
6 votes
187 views
3 bookmarks
Generalization to higher dimension of $e^r \not \in \mathbb Q$
1 answers
5 votes
472 views
3 bookmarks
Trace of nilpotent matrix over a ring
1 answers
4 votes
105 views
1 bookmarks
Number counting functions related to simple groups and asymptotic law of distribution
1 answers
3 votes
133 views
1 bookmarks
Infinitely many simple groups with conditions on order?
1 answers
2 votes
72 views
1 bookmarks
Mid point pentagon, maximization of perimeter under constraint
1 answers
2 votes
39 views
Polynomial (quartic) with complex coefficient: root localization
1 answers
2 votes
118 views
Does this function have a "name", somewhat linked to Euler totient
2 answers
2 votes
1k views
2 bookmarks
Groups of order 12 without Sylow
1 answers
2 votes
98 views
2 bookmarks
Non conjugate $p$-subgroups of $\mathrm{GL}_n(\mathbb Z)$
1 answers
1 votes
44 views
Pentagon on an ellipse: maximizing ratio of perimeters
0 answers
1 votes
78 views
Interesting (known?) polynomials
0 answers
0 votes
28 views
Measure of preimage of a surjective continuous function $f : \mathbb R^2 \to \mathbb R^2$
1 answers
0 votes
47 views
2 bookmarks
Iterating average
1 answers
-1 votes
65 views
Isomorphic finite rings?