lbeziaud

Hey, I don't understand why answers for math.stackexchange.com/q/2077769/108062 are using the Pòlya Enumeration Theorem, where A008289 has simple formulas for what seems to be the same question. Am I missing something?

Does someone knows if the set of the divisors of $n$ which are $k$-th power has a name or appears somewhere ?

Hi @Nocturne

Hi! Does someone know papers about transforming a graph into a cyclic graph ?

@anon (i) Yes. I will replace "times" by your "copies". (ii) Yes again. I could add "of $k$ not necessarily distinct multisets" to make it more obvious. Thanks!

Is this question understandable ? "Let $M'$ be a multiset of $k$ multisets such that the union of these multisets is equal to a given multiset $M$. How many ways are there to distribute a new element $n$ times between these multisets such that $M'$ does not contains duplicate multisets anymore?"

@Soham \; gives a nice spacing $\Bbb C^\times / \; \Bbb R^{\times} \cong S^1$

hi chat

@TedShifrin I had one with a PhD too

@Chris'ssistheartist Isn't that the same for all academic fields ?

@Hippalectryon Well, I don't

@Hippalectryon Miam

@Gato Oui

@Gato Le tutoriel "officiel" est très bien documenté sinon docs.python.org/3.5/tutorial

@EricStucky There might be an approval system...

Re-bonsoir

@Hippalectryon Oh thanks!

@TedShifrin Ok, thanks !

@TedShifrin Well I have this $H_d$ expression and I am searching a way to simplify $H_d(n,k) / k!$. I though it was possible to reduce it since $H_d$ contains $k!$ too. Sorry if I'm not clear

Should I make my quest for an advice a proper Math.SE question ?

Hi

@Huy Thanks a lot

@Huy Thanks, I'll look into that ! $H_d$ is already ugly, it will be fun

@Huy Do you have a hint to give me ? :)

Is there a way to get a definition of $P_d(k,n)$ knowing a definition of $H_d(n)$ and the following fact ? $$H_d(n)=\sum_{k=1}^n k! P_d(k,n)$$

@DanielFischer De même

I think I'll go for a sentence like "the inside sum is take over the d such that..." ;)

Arg

$$ H(k+1, n) = k! \sum_{j=0}^k \frac{(-1)^j}{(k-1-j)!} \sum_{\substack{d|n \\ d\geq 2 \\ d^{1/(j+1)} \in \mathbb{N}}} H(k-j, n/d) $$

@DanielFischer Is something like $\sum_{m^k \in\mathbb{N}}$ readable ?

@DanielFischer I was looking for something that can fit nicely as a $\sum$ condition

:22679296 $\exists m\in\mathbb{N}, n=m^k$

Is there a notation for "n is a k-th power" ?

@Fargle Oh yeah, thanks

Given $j\in\mathbb{N}$, does "$d^{1/(j+1)}$ is a natural number" means something for $d$ ?

@dREaM haha

Is there a standard way to turn a function which count ordered arrangements into one that count unordered arrangements ?

Hi

Hi @Mast

@chillworld hi

Hi

How can I define a function r[m_] to be "any" integer such that fr ≡ 1 (mod gm) ?

Hi