一个对称函数下界的加强

记ｆｋ（ｘ１…，ｘｎ）＝Ｅｋ（１－ｘ１，…，１－ｘｎ）－Ｅｋ（ｘ１，…，ｘｎ），ｋ＝１，…ｎ其中Ｅｋ（ｘ１，…，ｘｎ）为初等对称函数，并规定当ｋ＝０时，Ｅｋ（ｘ１，…，ｘｎ）＝１，当ｋ＜０或ｋ＞ｎ时，Ｅｋ（ｘ１，…，ｘｎ）＝０．笔者在文［１］证明了：...     

关于高阶Euler多项式的一点注记

对任何复数ｘ，考虑幂级数展开式：（２ｅｔ＋１）ｋｅｘｔ＝∑ｎ≥０Ｅ（ｋ）ｎ（ｘ）ｔｎｎ！｜ｔ｜＜π，则函数Ｅ（ｋ）ｎ（ｘ）称为ｋ阶Ｅｕｌｅｒ多项式［１］．特别地，Ｅ（１）ｎ（ｘ）＝Ｅｎ（ｘ）为普通Ｅｕｌｅｒ多项式；Ｅｎ＝２ｎＥｎ（１２）为Ｅｕ－ｌｅｒ...     

乘法分拆函数的均值估计

将正整数ｎ分拆成正整数的方法数记为ｇ（ｎ），本文对计数函数ｇ（ｎ）进行了均值估计。关于下限我们改进了［３］的结果。证明了对任意正整数ｋ皆有Σｎ≤ｘ１／ｎｇ（ｎ）≥３（４ｌｏｇ２ ｋ！２ｋ（ｋ＋１）／２）＾－１ｘｌｏｇ＾ｋｘ，ｘ≥１还获得了一个关于上限的结果Σｎ≤ｘ１／ｎｇ（ｎ）≤（ｋ－１）！Σ＾ｋ－１ｎ＝０１／ｎ！ｘ＾１／ｋ，ｘ≥１。     

相依样本下密度函数及其导函数的相合随机窗宽核估计

设（Ｘｎ）是Ｒ＾１中的平稳，强混合序列，具有公共的密度ｆ（ｘ），则可定义ｆ（ｘ）及其导函数ｆ＾（ｒ）（ｘ）的核估计与最近邻估计ｆ＾（ｒ）ｎ（ｘ）＝（ｎｈ＾ｒ＋１ｎ（ｘ））＾－１ｎ∑ｉ＝１Ｋ＾（ｒ）（Ｘｉ－Ｘ／ｈｎ（ｘ）），ｆｎ（ｘ）＝（ｎａｎ（ｘ））＾－１ｎ∑ｉ＝１Ｋ（Ｘｉ－ｘ／ａｎ（ｘ））其中核函数Ｋ（Ｘ）为取定的概率密度函数，且具有ｒ（ｒ≥０）阶导数，窗宽ｈｎ（ｘ）＝ｈｎ（ｘ；Ｘ１，．．．，Ｘ     

关于对称函数的一类不等式

关于对称函数的一类不等式石焕南（北京联大职业技术师院１０００１１）ｎ个正数ｘｌ，ｘＺ，…，ｘ。的初等对称函数是规定当ｋ＝０时，Ｅｋ（ｘｌ，…，。。）一１；当ｋ＜０或ｋ＞。时，Ｅｋ（。１，…，。。）一０．不难验证本文将证明如下两个定理定＆ＩＲ。；＞０，...     

短区间上非同构有限Abel群的个数

用算术函数ａ（ｎ）表示ｎ阶非同构Ａｂｅｌ群的个数，令Ａｋ（ｘ）＝∑／ｎ≤ｘ／ａ（ｎ）＝ｋ １，Ａｋ（ｘ；ｈ）＝Ａｋ（ｘ＋ｊ）－Ａｋ（ｘ）。     

n阶时滞差分方程的边值问题

本文研究ｎ阶时滞差分方程的边值问题：ｘ（ｋ＋ｎ）＝ｆ（ｋ，ｘｋ（），ｘ（ｋ），ｘ（ｋ＋１），…，ｘ（ｋ＋ｎ－１）），ｋ∈ＩＴ，ｘ（ｍ）＝φ（ｍ），ｍ∈Ｉ－ｒ，ｘ（１）＝ａ１，ｘ（２）＝ａ２，…，ｘ（ｎ－２）＝ａｎ－２，ｘ（Ｔ）＝Ａ，｛得到了解的存在性和唯一性的结果．     

某类有界拟凸域双全纯不变量的极限

Ｅ＝Ｅ（ｍ，ｎ，ｋ）＝｛（ｚ，ω）∈Ｃ＾ｎ＋ｍ：│ｚ│＾２＋│ω│＾２ｋ〈１，ｚ∈Ｃ＾ｎ，ω∈Ｃ＾ｍ，ｋ〉０｝是Ｃ＾ｍ＋ｍ中的一类有界拟凸域。该文证明了在δＥ的强拟凸点上，当ｍ〉１时，ｌｉｍ（ｚ，ω）→δＥＪＥ（（ｚ，ω））＝π＾ｎ＋ｍ（ｎ＋ｍ＋１）＾ｎ／（ｎ＋ｍ）！．ｍ＝１时，ｌｉｎ（ｚ，ω）→δＥＪＥ（ｚ，ω））＝π＾ｎ＋１（ｎ＝）＾ｎ＋１／（ｎ＋１）！，在δＥ的弱拟凸点上，上述极限不存在。     

Q_k(x)与F_k(x)的渐近公式

设ｎ，ｋ为自然数，Ｇ（ｎ）阶群中的同构类数，Ｆｋ（ｘ）与Ｑｋ（ｘ）分别表示不超过ｘ的自然数中使Ｇ（ｎ）＝ｋ的自然数、无平方因子自然数的个数．本文的目的是用Ｂｒｕｎ筛法证明Ｑｋ（ｘ）的条件渐近公式并对Ｆｋ（ｘ）的渐近性质做出了推测．     

Q3（X）的渐近公式

对于自然数ｎ，用Ｇ（ｎ）表示ｎ阶群中互不同构的群的个数（同构类数），用Ｑ＿３（ｘ）表示不超过ｘ的自然数（ｎ≤ｘ）中使Ｇ（ｎ）＝３的ｎ的个数．本文的目的是用筛法证明下面渐近公式：其中ｌｏｇ＿ｒｘ＝ｌｏｇ（ｌｏｇ＿（ｒ－１）ｘ），ｌｏｇ＿１ｘ＝ｌｏｇｘ，γ是Ｅｕｌｅｒ常数．     

On the Normal Order of ϕk+1(n)/ϕk(n), where ϕk is the k-Fold Iterate of Euler's Function

Let be the j-fold iterated function of . Let and > 0 be fixed, Q be a prime, and let N _k(Q|x) denote the number of those nx for which Q . We give the asymptotics of N _k(Q|x) in the range .     

The distribution functions of and

Let be the sum of the positive divisors of . We show that the natural density of the set of integers satisfying is given by , where denotes Euler's constant. The same result holds when is replaced by , where is Euler's totient function.

     

关于Makowski-Schinzel问题

对于正整数ｎ,设σ（ｎ）,ψ（ｎ）分别是ｎ的约数和函数和Ｅｕｌｅｒ函数,本文证明了：如果ｐ是ｎ的素因数,则必有σ（ψ（ｎｐ））／ｎｐ〉σ（ψ（ｎ））／ｎ。     

Oscillations of the remainder term related to the Euler totient function

We split the remainder term in the asymptotic formula for the mean of the Euler phi function into two summands called the arithmetic and the analytic part respectively. We show that the arithmetic part can be studied with a mild use of the complex analytic tools, whereas the study of the analytic part heavily depends on the properties of the Riemann zeta function and on the distribution of its non-trivial zeros in particular.     

On a sum involving the Euler totient function

In this short note, we prove that $\frac{4}{{\pi }^2}xlogx+O\left(x\right)?\sum _{n?x}\phi \left(\left[\frac{x}{n}\right]\right)?\left(\frac{1}{3}+\frac{4}{{\pi }^2}\right)xlogx+O\left(x\right),$ for $x\to \infty$, where $\phi \left(n\right)$ is the Euler totient function and $\left[t\right]$ is the integral part of real $t$. This improves recent results of Bordellès–Heyman–Shparlinski and of Dai–Pan.     

A Class of Rational Arithmetical Functions with Combinatorial Meanings

ＡＣｌａｓｏｆＲａｔｉｏｎａｌＡｒｉｔｈｍｅｔｉｃａｌＦｕｎｃｔｉｏｎｓｗｉｔｈＣｏｍｂｉｎａｔｏｒｉａｌＭｅａｎｉｎｇｓＰｅｎｔｉＨａｕｋｋａｎｅｎ（Ｄｅｐｔ．ｏｆＭａｔｈ．Ｓｃｉｓ．，Ｕｎｉｖ．ｏｆＴａｍｐｅｒｅ，Ｐ．Ｏ．Ｂｏｘ６０７，ＦＩＮ－...     

The limiting distribution of the divisor function

Let σα(n) be the sum of the αth power of the positive divisors of n. We establish an asymptotic formula for the natural density of the set of integers n that satisfy σα(n)/nα?t, as t→∞. Two other limiting distributions considered are based on Jordan's totient function and Dedekind's psi function.     

一类有理算术函数及其组合意义（英）

An arithmetical function f is said to be a rational arithmetical function of order (s,r) if there existcompletely multiplicative functions f₁,f₂,…,f_s and g₁,g₂,…,g_r such thatf=f₁*f₂*… *f_s*(g₁)^-1*(g₂)^-1*… *(g_r) -1 ,where * is the Dirichlet convolution. Recently, L.C. Hsu and Wang Jun studied combinatorial meanings of rational arithmetical functions of order (1,r) . We study these meanings in the setting of Narkiewicz's regular convolution.     

On -amicable pairs

Let denote Euler's totient function, i.e., the number of positive integers and prime to . We study pairs of positive integers with such that for some integer . We call these numbers -amicable pairs with multiplier , analogously to Carmichael's multiply amicable pairs for the -function (which sums all the divisors of ).

We have computed all the -amicable pairs with larger member and found pairs for which the greatest common divisor is squarefree. With any such pair infinitely many other -amicable pairs can be associated. Among these pairs there are so-called primitive -amicable pairs. We present a table of the primitive -amicable pairs for which the larger member does not exceed . Next, -amicable pairs with a given prime structure are studied. It is proved that a relatively prime -amicable pair has at least twelve distinct prime factors and that, with the exception of the pair , if one member of a -amicable pair has two distinct prime factors, then the other has at least four distinct prime factors. Finally, analogies with construction methods for the classical amicable numbers are shown; application of these methods yields another 79 primitive -amicable pairs with larger member , the largest pair consisting of two 46-digit numbers.

     

一个包含欧拉函数的方程

设n为任意正整数,如果n〉1,设n=p1^α1p2^α2…pk^αk是n的标准分解式,函数Ω（n）定义为Ω（1）=0,Ω（n）=∑i=1^kαi,φ（n）为Euler函数,本文的主要目的是利用初等方法研究方程φ（φ（n））=2Ω（n）的可解性,并获得该方程的所有正整数解,从而彻底解决了前学者提出的一个问题．