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0 votes
0 answers
50 views

How to integrate $\frac{x^N\log(1+x)}{\sqrt{x^2+x_1^2}\sqrt{x^2+x_2^2}}$?

I am trying to compute the integral $$\int_{x_0}^{1}\frac{x^N\log(1+x)}{\sqrt{x^2+x_1^2}\sqrt{x^2+x_2^2}}\text{d}x$$ where $x_0, x_1$ and $x_2$ are related to some parameters $\kappa_\pm$ by $$x_0=\...
Anders W's user avatar
0 votes
1 answer
93 views

$\sum_{i=1}^{n} \frac {x^{2i-1}}{\sqrt{2i}}$ as polylogarithm

$$\sum_{i=1}^{n} \frac {x^{2i-1}}{\sqrt{2i}}$$ It is very clear for me that it has to be polylogarithm function but as it is partial sum I tried to split the series as $$\sum_{i=1}^{\infty} \frac {x^{...
Adolf L.'s user avatar
1 vote
1 answer
70 views

Evaluating $\sum_{k=1}^{a}\frac{-1-H_k}{k(1-e)^k}$

Question : My attempt: Let $a=17399172$ $$\begin{align} &\sum_{k=1}^{a}\frac{-1-H_k}{\log_2\left(\sum_{j=0}^{k}\left(\ln\left(e^{C_j^k}\right)\right)\right)(1-e)^k} \\ &= \sum_{k=1}^{a}\frac{-...
user516076's user avatar
  • 2,200
5 votes
1 answer
427 views

Evaluate $\int_0^1 \log (1-x)\ _3F_2\left(1,1,1;\frac{3}{2},\frac{3}{2};x\right) \, dx$

I encountered a hypergeometric integral while investigating harmonic sums $$\int_0^1 \log (1-x)\ _3F_2\left(1,1,1;\frac{3}{2},\frac{3}{2};x\right) \, dx$$ Based on my experience I suspect a nice ...
Infiniticism's user avatar
  • 8,654
2 votes
1 answer
225 views

Hyperbolic series similar to Ramanujan’s identities

I want to prove this ,but nothing’s came up in my mind Could Anyone give me a hint or a solution please .i saw another sum looks like this and was solved by hypergeometric function and Residue .i ...
Unik Sillavich's user avatar
10 votes
1 answer
576 views

Evaluate $\int_0^1 x^{a-1}(1-x)^{b-1}\operatorname{Li}_3(x) \, dx$

Define $\small f(a,b)=\frac1{B(a,b)}\int_0^1 x^{a-1}(1-x)^{b-1} \text{Li}_3(x) \, dx$$ $$=\frac a{a+b}{}_5F_4(1,1,1,1,a+1;2,2,2,1+a+b;1)$ Where $a>-1$ and $b>0$. $1$. By using contour ...
Kemono Chen's user avatar
  • 8,669
10 votes
1 answer
476 views

A twisted hypergeometric series $\sum_{n=1}^\infty\frac{H_n}{n}\left(\frac{(2n)!}{4^n(n!)^2}\right)^2$

Question. I was given that $$S=\sum_{n=1}^\infty\frac{H_n}{n}\left(\frac{(2n)!}{4^n(n!)^2}\right)^2=\frac{32}\pi G\ln2+\frac{64}\pi\Im\operatorname{Li}_3\left(\frac{1+i}2\right)-2\ln^22-\frac53\pi^2$$ ...
Kemono Chen's user avatar
  • 8,669
14 votes
1 answer
479 views

Yet another difficult logarithmic integral

This question is a follow-up to MSE#3142989. Two seemingly innocent hypergeometric series ($\phantom{}_3 F_2$) $$ \sum_{n\geq 0}\left[\frac{1}{4^n}\binom{2n}{n}\right]^2\frac{(-1)^n}{2n+1}\qquad \...
Jack D'Aurizio's user avatar
6 votes
2 answers
3k views

Lagrange Inversion Theorem Proof

Note: throughout this question, I'll be using the following notation convention: $$f^{(n)}(x)=\frac{d^nf}{dx^n}(x)$$ I was browsing through Wikipedia and even MSE's related questions searching for a ...
46andpi's user avatar
  • 158
13 votes
2 answers
522 views

On the integral $\int_{0}^{1/2}\frac{\text{Li}_3(1-z)}{\sqrt{z(1-z)}}\,dz$

This questions is related to my previous one. I am interested in a explicit evaluation in terms of Euler sums for $$ \int_{0}^{\pi/4}\text{Li}_3(\cos^2\theta)\,d\theta = \frac{1}{2}\int_{0}^{1/2}\...
Jack D'Aurizio's user avatar
2 votes
1 answer
182 views

About the integral $\int\arctan\left(\frac{1}{\sinh^2 x}\right)dx$, some idea or feedback

While I was playing with Wolfram Alpha calculator I wondered if it is known a closed-form for $$\int_0^\infty\arctan\left(\frac{1}{\sinh^2 x}\right)dx.\tag{1}$$ Wolfram Alpha provide me the ...
user avatar
20 votes
2 answers
1k views

Closed form for $\sum_{n=0}^\infty\frac{\Gamma\left(n+\tfrac14\right)}{2^n\,(4n+1)^2\,n!}$

I was experimenting with hypergeometric-like series and discovered the following conjecture (so far confirmed by more than $5000$ decimal digits): $$\sum_{n=0}^\infty\frac{\Gamma\!\left(n+\tfrac14\...
Vladimir Reshetnikov's user avatar
26 votes
2 answers
1k views

Integral ${\large\int}_0^1\ln^3\!\left(1+x+x^2\right)dx$

I'm interested in this integral: $$I=\int_0^1\ln^3\!\left(1+x+x^2\right)dx.\tag1$$ Can we prove that $$\begin{align}I&\stackrel{\color{gray}?}=\frac32\ln^33-9\ln^23+36\ln3+2\pi^2\ln3-\frac{4\pi^2}...
Vladimir Reshetnikov's user avatar
25 votes
2 answers
728 views

Definite integral of arcsine over square-root of quadratic

For $a,b\in\mathbb{R}\land0<a\le1\land0\le b$, define $\mathcal{I}{\left(a,b\right)}$ by the integral $$\mathcal{I}{\left(a,b\right)}:=\int_{0}^{a}\frac{\arcsin{\left(2x-1\right)}\,\mathrm{d}x}{\...
David H's user avatar
  • 30.7k