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Mikko Korhonen's user avatar
Mikko Korhonen's user avatar
Mikko Korhonen's user avatar
Mikko Korhonen
  • Member for 12 years, 7 months
  • Last seen this week
125 votes
Accepted

Prove that $\sqrt 2 + \sqrt 3$ is irrational

115 votes
Accepted

How to show that the commutator subgroup is a normal subgroup

64 votes
Accepted

Is a finite group uniquely determined by the orders of its elements?

56 votes
Accepted

Is there an idempotent element in a finite semigroup?

36 votes

Conjugate subgroup strictly contained in the initial subgroup?

32 votes

More than 99% of groups of order less than 2000 are of order 1024?

28 votes
Accepted

When is the group of units in $\mathbb{Z}_n$ cyclic?

25 votes
Accepted

Groups with given automorphism groups

24 votes

Prove $2^{1/3}$ is irrational.

23 votes

Is there a formula for $(1+i)^n+(1-i)^n$?

23 votes
Accepted

If $S$ is a nonempty subset of group $G$, then $S^{|G|}$ is a subgroup of $G$.

20 votes
Accepted

Conjugacy classes of a $p$-group

20 votes

How to prove $|z_1-z_2| \geq |z_1|-|z_2|$ in other way than this?

20 votes
Accepted

Number of Homomorphisms from $\Bbb{Z}_m$ to $\Bbb{Z}_n$

19 votes
Accepted

Every group of order 255 is commutative

18 votes
Accepted

If a finite group $G$ is solvable, is $[G,G]$ nilpotent?

17 votes
Accepted

Proving that a group of order $112$ is not simple

15 votes

Subgroups of a cyclic group and their order.

15 votes
Accepted

Finite groups with all maximal subgroups of prime power index are solvable?

15 votes
Accepted

Calculate the 146th digit after the decimal point of $ \frac{1}{293} $

14 votes
Accepted

Normal subgroup of prime order is characteristic

14 votes
Accepted

Is there an abelian and a nonabelian group with same numbers of elements of each order.

14 votes
Accepted

Terminology for infinite groups, all of whose subgroup have finite index.

13 votes

What is the standard notation to represent the set of primes?

13 votes
Accepted

Given 3 distinct primes {$p,q,r$}, then $|G|=pqr \implies G$ not simple

13 votes

Upper bounds on the size of $\operatorname{Aut}(G)$

13 votes
Accepted

No group of order 400 is simple

13 votes

Why $\gcd(b,qb+r)=\gcd(b,r),\,$ so $\,\gcd(b,a) = \gcd(b,a\bmod b)$

13 votes
Accepted

Main branches of mathematics

12 votes
Accepted

Conjugacy classes of non-Abelian group of order $p^3$

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