List questions from arithmetic-functions

Published on 25 Sep 2016 - 6:56

41

Views

For which natural numbers $N$ does $D(N)=2N-\sigma_{1}(N) \mid N$ hold?

Published on 26 Sep 2016 - 8:32

266

Views

Prove that a $\limsup$ related with the sum of divisor function equals $e^{\gamma}$

Published on 02 Oct 2016 - 20:10

1.1k

Views

An application of Mobius Inversion $\sum_{d \mid n} \mu(\frac{n}{d})\nu(d) = 1$

Published on 26 Mar 2026 - 3:12

466

Views

Does the Mobius Inversion Theorem hold when sum function is over multiples instead of divisors

Published on 25 Mar 2026 - 13:44

30

Views

Lower bound on sum of $k$ largest entries

Published on 13 Oct 2016 - 23:54

302

Views

Venn diagram question with approximate ranges

Published on 25 Oct 2016 - 17:13

410

Views

Mediant and arithmetic mean of several fractions

Published on 25 Mar 2026 - 16:46

38

Views

Prove that if $\sigma(x) \le 2x$ and $n|x$ where $n\neq x$, then $\sigma(n)<2n$.

Published on 27 Oct 2016 - 18:51

87

Views

Proof that arithmetic mean of σ(n) & φ(n) is >=n

Published on 28 Oct 2016 - 19:15

1.5k

Views

Formula for square of the number of divisors $\sum_{r\mid n} d(r^2) = d^2(n)$

Published on 25 Mar 2026 - 13:46

129

Views

$\sum\limits_{n=1}^\infty\dfrac{\nu(n)}{n^s}=\zeta(s)^2$ for $s$ real

Published on 06 Nov 2016 - 21:18

324

Views

Let n be a positive integer. Determine the number of ordered pairs (a, b) of positive integers with lcm(a, b) = n as a function of τ .

Published on 21 Nov 2016 - 0:31

110

Views

Möbius Inversion with Additional Term

Published on 25 Mar 2026 - 13:04

69

Views

Diophantine equation involving arithmetical functions

Published on 02 Dec 2016 - 14:40

List Question

Is there a mathematical function which flips 1 and 2?

For which natural numbers $N$ does $D(N)=2N-\sigma_{1}(N) \mid N$ hold?

Prove that a $\limsup$ related with the sum of divisor function equals $e^{\gamma}$

An application of Mobius Inversion $\sum_{d \mid n} \mu(\frac{n}{d})\nu(d) = 1$

Does the Mobius Inversion Theorem hold when sum function is over multiples instead of divisors

Lower bound on sum of $k$ largest entries

Venn diagram question with approximate ranges

Mediant and arithmetic mean of several fractions

Prove that if $\sigma(x) \le 2x$ and $n|x$ where $n\neq x$, then $\sigma(n)<2n$.

Proof that arithmetic mean of σ(n) & φ(n) is >=n

Formula for square of the number of divisors $\sum_{r\mid n} d(r^2) = d^2(n)$

$\sum\limits_{n=1}^\infty\dfrac{\nu(n)}{n^s}=\zeta(s)^2$ for $s$ real

Let n be a positive integer. Determine the number of ordered pairs (a, b) of positive integers with lcm(a, b) = n as a function of τ .

Möbius Inversion with Additional Term

Diophantine equation involving arithmetical functions

Trending Questions

Popular # Hahtags

Popular Questions