Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 65801

For questions on divisors and multiples, mainly but not exclusively of integers, and related and derived notions such as sums of divisors, perfect numbers and so on.

3 votes
Accepted

On odd perfect numbers $N$ given in the Eulerian form $N = {q^k}{n^2}$, Part II

In general there is a factorization $\sigma(q^{k-1}) = 1+q+\ldots+q^{k-1} = \frac{q^k-1}{q-1} = \prod_{d\mid k, d>1} \Phi_d(q)$. Here $\Phi_d$ is the $d$'th cyclotomic polynomial, defined as the minim …
Kasper Andersen's user avatar