Jyrki Lahtonen

 153 The limit of truncated sums of harmonic series, $\lim\limits_{k\to\infty}\sum_{n=k+1}^{2k}{\frac{1}{n}}$ 126 Is there any mathematical reason for this “digit-repetition-show”? 91 Math behind rotation in MS Paint 62 How do we prove $n^n \mid m^m \Rightarrow n \mid m$? 61 How can you show there are only 2 nonabelian groups of order 8?

### Reputation (112,016)

 +10 Getting the inverse of a lower/upper triangular matrix +10 An exercise on cyclic extensions of Hungerford's book, Algebra. +15 Covering radius and Binary Even weight codes +10 Determine the splitting field of $x^4 - 7$ over

### Questions (15)

 38 On the norm of a quotient of a Banach space. 27 Is it possible for an irreducible polynomial with rational coefficients to have three zeros in an arithmetic progression? 20 Discrete logarithm tables for the fields $\Bbb{F}_8$ and $\Bbb{F}_{16}$. 17 Connected unbounded sets $S\subset \Bbb{R}^n$ such that $x\mapsto ||x||^t$ is uniformly continuous on $S$? 16 Is there a group homomorphism $\Bbb{C}^*\to\Bbb{R}^*$ with a countable kernel?

### Tags (487)

 3k abstract-algebra × 711 851 galois-theory × 282 1k finite-fields × 502 839 linear-algebra × 254 1k group-theory × 310 804 polynomials × 241 1k field-theory × 325 797 elementary-number-theory × 233 1k number-theory × 236 489 matrices × 108

### Accounts (40)

 Mathematics 112,016 rep 14184404 MathOverflow 1,214 rep 814 Mathematics Educators 1,117 rep 817 Politics 708 rep 37 Meta Stack Exchange 646 rep 412