# Zur Dichte der Menge der vollkommenen Zahlen

```@article{Hornfeck1955ZurDD,
title={Zur Dichte der Menge der vollkommenen Zahlen},
author={Bernhard Hornfeck},
journal={Archiv der Mathematik},
year={1955},
volume={6},
pages={442-443}
}```
11 Citations
Paul Erdős and the Rise of Statistical Thinking in Elementary Number Theory
• Mathematics
• 2013
It might be argued that elementary number theory began with Pythagoras who noted two-and-a-half millennia ago that 220 and 284 form an amicable pair. That is, if s(n) denotes the sum of the proper
Rationally almost periodic sequences, polynomial multiple recurrence and symbolic dynamics
• Mathematics
Ergodic Theory and Dynamical Systems
• 2019
A set \$R\subset \mathbb{N}\$ is called rational if it is well approximable by finite unions of arithmetic progressions, meaning that for every \$\unicode[STIX]{x1D716}>0\$ there exists a set \$B=\bigcup
Reciprocal Sums as a Knowledge Metric: Theory, Computation, and Perfect Numbers
• Mathematics
Am. Math. Mon.
• 2013
A new use for reciprocal sums is introduced; that is, they can be used as a knowledge metric to classify the current state of number theorists’ understanding of a given class of integers.
THE RISE OF STATISTICAL THINKING
When faced with remarkable examples such as this it is natural to wonder how special they are. Through the centuries mathematicians tried to find other examples of amicable pairs, and they did indeed
Wie kann man Primzahlen erkennen
Dass die Aufgabe, die Primzahlen von den zusammengesetzten zu unterscheiden und letztere in ihre Primfactoren zu zerlegen, zu den wichtigsten und nutzlichsten der gesamten Arithmetik gehort und die
How to Recognize Whether a Natural Number is a Prime
The problem of distinguishing prime numbers from composite numbers and of resolving the latter into their prime factors is known to be one of the most important and useful in arithmetic.
Über die Häufigkeit vollkommener Zahlen
• Economics
• 1957
Decatizing apparatus comprises a steaming cylinder and a suction cylinder. Respective primary backing cloths are associated with the steaming and suction cylinders to press the fabric to be treated

## References

SHOWING 1-2 OF 2 REFERENCES
On the density of some sequences of numbers
The fun&ions f(m) and 4(m) are called additive and multiplicative respectively if they are defined for non-negative integers m, and if, for (ml, m,) = 1, fhm,) =f(W+fhL In my paper " On the density