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qifeng618
  • Member for 5 years, 1 month
  • Last seen more than a week ago
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About

I am a Chinese mathematician. My full name in English is Feng Qi. For more information on me, please visit the following sites:

https://research.com/u/feng-qi

https://qifeng618.wordpress.com

https://www.researchgate.net/profile/Feng_Qi

https://orcid.org/0000-0001-6239-2968

https://scholar.google.com/citations?user=Q-wGSBYAAAAJ

https://www.webofscience.com/wos/author/record/G-2455-2012

https://www.growkudos.com/profile/feng_qi

https://www.semanticscholar.org/author/Feng-Qi/143785202

http://www.scopus.com/authid/detail.url?authorId=7101777278

http://www.ams.org/mathscinet/search/author.html?mrauthid=610520

https://zbmath.org/authors/?q=ai:qi.feng

Welcome your visits.

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Top posts
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question
7
Is the Gauss hypergeometric series ${}_2F_1\bigl(\frac{1}{2},\frac{1}{2};2;t\bigr)$ an elementary function?
Jun 1, 2022
question
5
How to prove the combinatorial identity $\sum_{k=\ell}^{n}\binom{2n-k-1}{n-1}k2^k=2^\ell n\binom{2n-\ell}{n}$ for $n\ge\ell\ge0$?
Aug 30, 2021
answer
4
Is the function $(z-1)(2^{z}-1)\zeta(z)$ logarithmically concave and convex in $z\in(0,\infty)$?
Oct 5
answer
4
$n$-th derivative of $\exp\left(-\frac{\lambda(x-\mu)^2}{2\mu^2x}\right)$
Apr 21
question
4
Ask for a generating function or an explicit expression of a triangle of positive integers
Dec 13, 2022
question
4
What is the inverse of a triangular matrix whose nonzero elements are binomial coefficients? What is the closed-form solution to a recursive relation?
Dec 16, 2022
question
4
What or where is the series expansion of the function $\ln\bigl(\frac{\tan x}{x}-1\bigr)$ or $\ln(\tan x-x)$ around $x=0$?
Apr 7, 2023
answer
4
How to prove the combinatorial identity $\sum_{k=\ell}^{n}\binom{2n-k-1}{n-1}k2^k=2^\ell n\binom{2n-\ell}{n}$ for $n\ge\ell\ge0$?
Aug 30, 2021
question
3
Ask for a reference or a proof of a combinatorial identity $\sum_{k=0}^n\binom{2n+1}{2k}\binom {k}{m} =2^{2(n-m)}\frac{2n+1}{2(n-m)+1}\binom{2n-m}{m}$
Nov 20, 2021
question
3
Where to find or how to prove that the ratio of two Bernoulli polynomials is increasing?
Jan 2
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8
What is the general formula of the sum $\sum_{k=0}^{n}(-1)^{k} \binom{n}{k}\binom{k/2}{m}$ for $m,n\in\mathbb{N}$?
7
Can we prove AM-GM Inequality using these integrals?
5
Ask for a proof of logarithmically complete monotonicity of a power-exponential function involving the difference of the psi and logarithmic functions
5
A guess on two increasing rational approximations to $\frac{\pi}{4}$