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0 votes
0 answers
64 views

$Li(x)$ function and Bell polynomials

I found one formula connecting the logarithmic integral function, $li(x)$, to polynomials as following: $$li(x) = \frac{x}{\ln(x)} + \sum_{k=1}^{+\infty} \frac{P_k(\ln(x))}{x^k}$$ where $P_k(x)$ is ...
Craw Craw's user avatar
1 vote
1 answer
235 views

Number of unordered factorizations of a non-square-free positive integer

I recently discovered that the number of multiplicative partitions of some integer $n$ with $i$ prime factors is given by the Bell number $B_i$, provided that $n$ is a square-free integer. So, is ...
Scene's user avatar
  • 1,611
3 votes
1 answer
78 views

representation through special numbers

Let $n,r\in N$ and let $S(n,m)$ represent Stirling's number of the second kind. It is known that $\sum_{m=0}^n S(n,m)m!=F_n$ is a Fubini number. Is it possible to represent (or estimate from above) ...
Forbs's user avatar
  • 311
0 votes
1 answer
85 views

Literature on bounds of Fubini's numbers

If anybody can suggest where I can find a literature for a known upper and lower bounds on Fubini numbers https://en.wikipedia.org/wiki/Ordered_Bell_number
user4164's user avatar
  • 301
1 vote
0 answers
78 views

Is the number of sub-boolean algebra of a set with size n , Bell(n)?

In boolean algebra (P(S),+,.,’) we must have S as 1 and {} as 0 in every possible sub-boolean algebra to hold id elements. We must have S-x for every subset x⊆S to hold complements. It seems like ...
Omid Yaghoubi's user avatar
3 votes
2 answers
417 views

Calculating large Bell number modulo a composite number

I have been trying to solve http://www.javaist.com/rosecode/problem-511-Bell-Numbers-Modulo-Factorial-askyear-2018 It is not an ongoing contest problem. We can calculate $n$th Bell number modulo a ...
piepie's user avatar
  • 547
2 votes
1 answer
532 views

Exponential generating function for the Bell numbers

I've recently come across the Bell numbers, defined as: \begin{equation*} B_{n+1} = \sum_{k=0}^{n}\binom{n}{k}B_{k}. \end{equation*} The exponential generating function of the Bell numbers is known to ...
user3523464's user avatar