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Sep
18
comment What are all positive integers n for which the congruence $a^{n+1} \equiv a (mod n)$ holds?
so do you fix a?
Sep
18
comment Decomposition of symmetric homogeneous polynomials
"Someone else" is most likely Krein
Aug
31
awarded  Yearling
Jun
29
comment Fixed points of $x\mapsto 2^{2^{2^{2^x}}} \mod p$
In fact, for one exponent, one can use quantitate Roth to improve the bound to p/\log\log p
May
2
awarded  Scholar
May
2
comment Modern reference request concerning Efimov's “On dyadic spaces”
Thanks a lot, Rafael!
May
2
accepted Modern reference request concerning Efimov's “On dyadic spaces”
May
1
comment Modern reference request concerning Efimov's “On dyadic spaces”
A space $X$ is called dyadic if it is a continuous image of the space $\{0,1\}^I$ for some set $I$. Compact metric spaces and compact topological groups are among dyadic spaces. I would really appreciate if you can scan the paper for me.
May
1
asked Modern reference request concerning Efimov's “On dyadic spaces”
Apr
12
awarded  Citizen Patrol
Mar
13
comment A sumset inequality
well, with high probability random set is Sidon, so it is not surprising that the inequality holds. Have you tried looking at the extremal examples in Feiman 3n-3 theorem?
Mar
5
comment Fourier inversion
Everything you are asking for can be found in Katznelson book on Harmonic analysis, which is I believe available online.
Feb
14
comment $ 2|f^{'}(0)| = \sup_{z, w \in D} |f(z)-f(w)|$ if and only if $f$ is linear
Out of curiosity, would not it be simpler to give a direct proof to the fact rather than looking for the reference?
Dec
29
comment Estimate the sum $\sum_{k=1}^n \frac{2^k}{k}$
take a look at the sum $\int_1^x(1+t+t^2+...t^{n-1})dt$
Dec
27
comment When is the product (1+1)(1+4)…(1+n^2) a perfect square?
In fact, the first to improve Chebushev's result was Nagell (reference [4] from Cilleruelo paper), who showed that the largest prime factor of the product $\prod f(j)$ is $\ge n\log n.$ Ciruello's proof goes along Nigell's one by making the estimate precise and using computer search for small $n.$
Dec
22
comment cyclotomic polynomials of given degree
This arxiv.org/pdf/math/0404116v3.pdf paper of Contini, Croot and Shparlinki produces a polynomial time algorithm to compute $n$ for "almost all d" (the authors also give complexity for all $d.$)
Dec
15
answered Accurate bounds for derivatives of Legendre polynomials
Dec
4
comment Irreducible polynomials with a root modulo almost all primes
In fact even more is true. One can prove that if $f$ is irreducible, then $f$ has roots for roughly $1/deg f$ primes.
Nov
8
comment Weak amenability and quasi central bounded approximate identity
I'm glad to hear it Albert:)
Nov
6
answered The equation $x^m-1=y^n+y^{n-1}+…+1$ in prime powers $x,y$