Results 11 to 20 of about 37 (34)

On a thin set of integers involving the largest prime factor function

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 19, Page 1185-1192, 2003., 2003
For each integer n ≥ 2, let P(n) denote its largest prime factor. Let S : = {n ≥ 2 : n does not divide P(n)!} and S(x) : = #{n ≤ x : n ∈ S}. Erdős (1991) conjectured that S is a set of zero density. This was proved by Kastanas (1994) who established that S(x) = O(x/logx). Recently, Akbik (1999) proved that S(x)=O(x exp{−(14/)logx}).
Jean-Marie De Koninck, Nicolas Doyon
wiley   +1 more source

On a density problem of Erdös

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 22, Issue 3, Page 655-658, 1999., 1999
For a positive integer n, let P(n) denotes the largest prime divisor of n and define the set: 𝒮(x) = 𝒮 = {n ≤ x : n does not divide P(n)!}. Paul Erdös has proposed that |S| = o(x) as x → ∞, where |S| is the number of n ∈ S. This was proved by Ilias Kastanas. In this paper we will show the stronger result that .
Safwan Akbik
wiley   +1 more source

Sec. 3 -T 23 N-R 16 E, Rogers County, Oklahoma

open access: yes, 2021
------------------------------ SEC. 3 -T 23 N-R 16 E, ROGERS COUNTY,OKLAHOMA 5,280.001 2,640.001 N 89° 551 4211 E 2,640.00 UJ ---N -r,.. -a> ,i, o ro 0 U) Oc-i z >J(. N r,.. ~ N IO LLl­: 0) q 00 -,;t ~ U) o cJ' o* z ~ r-I I I I I I I .1 I I I I I I I I I

core  

On the distribution of powered numbers

open access: yesOpen Mathematics
Asymptotic formulae are established for the number of natural numbers mm with largest square-free divisor not exceeding mϑ{m}^{{\vartheta }}, for any fixed positive parameter ϑ{\vartheta }. Related counting functions are also considered.
Brüdern Jörg, Robert Olivier
doaj   +1 more source

On the ratio of the sum of divisors and Euler’s totient function II [PDF]

open access: yes, 2014
We find the form of all solutions to ø(n) | σ(n) with three or fewer prime factors, except when the quotient is 4 and n is ...
Qizhi Zhou   +3 more
core  

On the ratio of the sum of divisors and Euler’s Totient Function I [PDF]

open access: yes, 2013
We prove that the only solutions to the equation σ(n)=2φ(n) with at most three distinct prime factors are 3, 35 and 1045. Moreover, there exist at most a finite number of solutions to σ(n)=2φ(n) with Ω(n)≤ k, and there are at most 22k+k-k squarefree ...
Delbourgo, Daniel, Broughan, Kevin A.
core  

Arithmetically Related Ideal Topologies and the Infinitude of Primes

open access: yes, 2004
The late J. Knopfmacher and the author [12] have studied some ties between arithmetic properties of the multiplicative structure of commutative rings with identity and the topologies induced by some coset classes. In the present communication it is
Porubský, Stefan
core  

Genetic population structure of the malaria vector Anopheles baimaii in north-east India using mitochondrial DNA. [PDF]

open access: yesMalar J, 2012
Sarma DK   +11 more
europepmc   +1 more source

Coupling of Nondegenerate Topological Modes in Nitrogen Core-Doped Graphene Nanoribbons. [PDF]

open access: yesACS Nano
Jacobse PH   +9 more
europepmc   +1 more source

Dose-Response Effect of Glucagon on Glucose, Beta-Cell Secretion and Metabolism in Healthy Individuals. [PDF]

open access: yesDiabetes Obes Metab
Brock SB   +4 more
europepmc   +1 more source

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