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2 votes
2 answers
215 views

Is $\lim_{n\to\infty}\left\{n!\sum_{k=1}^{n!}\frac{1}{k^{\frac{3}{2}}}\right\}$ not convergent?

I need to calculate the limit (if it exist) $$\lim_{n\to\infty}\left\{n!\sum_{k=1}^{n!}\frac{1}{k^{\frac{3}{2}}}\right\}$$ where $\{x\}$ denotes the fractional part of $x$, $n!$ is the factorial of $n$...
Max's user avatar
  • 928
6 votes
2 answers
279 views

$\lim_{n\to\infty}\left\{n\sum_{k=1}^n\frac{1}{k^5}\right\}$

I need to calculate the limit (if it exist) $$\lim_{n\to\infty}\left\{n\sum_{k=1}^n\frac{1}{k^5}\right\}$$ where $\{x\}$ denotes the fractional part of $x$ and $n\in\mathbb{N}$. By definition of ...
Max's user avatar
  • 928
6 votes
4 answers
300 views

Limit of lacunar power series in $1^-$.

Let $\sigma:\mathbb{N}\longrightarrow\mathbb{N}$ be strictly increasing, and consider the power series $$ S_{\sigma}(x)=\sum_{n=0}^{+\infty}(-1)^nx^{\sigma(n)}. $$ Can any real number in $[0,1]$ be ...
Tuvasbien's user avatar
  • 9,357
6 votes
0 answers
194 views

Proof of Theorem 1.1 of Analytic Number Theory by Iwaniec & Kowalski

I am not clear about the proof of Theorem 1.1 in the book `Analytic Number Theory' by the authors Iwaniec & Kowalski. They say that if a multiplicative function $f$ satisfies $$\sum_{n\le x}\...
Kangyeon Moon's user avatar
1 vote
2 answers
106 views

What is the limit of $\frac{\Omega(n!)}{n}$ as $n \to \infty$?

Let $p_i$ be the $i$th prime number, and $\Omega(n) =$ the total number of prime factors of $n$ counting multiplicities. We know that $\Omega(n)$ is completely additive, so:   $$ \frac{\Omega(n!)}{n} ...
SeekingAMathGeekGirlfriend's user avatar
2 votes
1 answer
132 views

Analytic Number Theory [closed]

I really need help with two problems that I can't solve. I have the following function: $$R(N) = \sum_{n=1}^N\exp(2\pi i\sqrt{n})$$ I was able to show that $R(n)=O(\sqrt{n})$, but I am also being ...
AndrewGap's user avatar
  • 111
6 votes
0 answers
142 views

How fast does the coprime probability converge to $6/\pi^2$?

It is known that the probability that two positive integers are coprime is $6/\pi^2$. This is an amazing result. I wanted to see experimentally how the probability converges to $6/\pi^2$, but I found ...
Martin Brandenburg's user avatar
2 votes
1 answer
106 views

Does $\lim_{k\rightarrow\infty}\frac{\log(P_1(k))}{\log(k)}$ exist?

Wikipedia gives the definition of the Golomb-Dickman constant as $$\lambda=\lim_{n\rightarrow\infty}\frac1n\sum_{k=2}^n\frac{\log(P_1(k))}{\log(k)}$$Where $P_1(x)$ is the largest prime factor of $x$. ...
Kamal Saleh's user avatar
  • 6,549
3 votes
1 answer
346 views

Does the mean ratio of the largest prime factor in prime gaps to the lower bound of the gap converge?

Note: Posted in MO since (2) is open in MSE Let $p_n$ be the $n$-th prime and $p_n < c_n < p_{n+1}$ be the composite number such that $c_n$ has the largest prime factor $l_n$ in this prime gap. ...
Nilotpal Sinha's user avatar
2 votes
1 answer
86 views

Compute limit of a function of the first $n$ prime numbers

Just playing with the result in this answer, I am asking some help for computing: $$\lim_{n \to \infty}\frac{\prod_{k=1}^{n} p_{k}^{\frac{p_k}{(p_k-1)^2}}}{p_n}$$ where $p_k$ is the $k$-th prime ...
Fabius Wiesner's user avatar
4 votes
2 answers
118 views

What is the limiting mean value of the product of the exponents in the prime factorization of numbers?

Let $n = p_1^{a_1}p_2^{a_2}\cdots p_m^{a_m}$ be the prime factorization of $n$ and let $f(n) = a_1 a_2 \cdots a_m$. Using a heuristic argument I am able to show that the mean value of $\lim_{n \to \...
Nilotpal Sinha's user avatar
0 votes
0 answers
79 views

Sum versus product on Primes

Disclaimer: I had a hard time choosing the title. Hello MSE! So in this post I was wondering why $e^\gamma$ has importance in number theory while $\gamma$ and $e$ don't. But I have another question ...
Kamal Saleh's user avatar
  • 6,549
1 vote
1 answer
136 views

Elementary proof that $\lim_{n \to \infty} \prod_{i=1}^n (1-\frac{1}{p_i}) = 0$

Is there an elementary proof that for primes $p_i$, $$\lim_{n \to \infty} \prod_{i=1}^n \left(1-\frac{1}{p_i}\right)=0\;?$$ This follows from Mertens third theorem which states that $$ \prod_{i=1}^n \...
Simd's user avatar
  • 437
5 votes
2 answers
199 views

Radical of Infinite Product of Primes

I somehow stumbled across this thing. $$\lim_{n \to \infty}({p_1\times p_2\times p_3\times\cdots \times p_n})^{\frac{1}{p_n}}$$ Where $p_i$ is the $i$-th prime. I wanted to know if this converges or ...
Adi's user avatar
  • 71
2 votes
0 answers
154 views

How is this indefinite integral a holomorphic function?

In an analytic number theory textbook we derived the formula $$\zeta(s)=\frac{s}{s-1}-s\int_1^\infty \{x\}x^{-s-1}\mathrm{dx}$$ and the textbook says, that the integral on the right side converges ...
HyperPro's user avatar
  • 901

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