Question

Reference request: Do any papers on odd perfect numbers approach the problem using the following equation?

score 66 · Answer 1 · 2026-03-26 20:19:56

66

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Reference request: Do any papers on odd perfect numbers approach the problem using the following equation?

Published on 26 Mar 2026 - 20:19

score 1.5k · Answer 2 · 2026-03-29 10:48:16

1.5k

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An integer is prime iff $\phi(n) \mid n-1$ and $n+1 \mid \sigma (n)$

Published on 29 Mar 2026 - 10:48

score 494 · Answer 3 · 2015-11-18 02:48:40

494

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Fourier transform for sum-of-divisors function

Published on 18 Nov 2015 - 2:48

score 87 · Answer 4 · 2015-11-28 01:20:59

87

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Fourier series concerning Gibbs constant and the divisor function.

Published on 28 Nov 2015 - 1:20

score 100 · Answer 5 · 2015-12-05 18:53:57

100

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What is an upper bound for $\frac{4x - \sigma(x)}{3x - \sigma(x)}$ when $x$ is deficient?

Published on 05 Dec 2015 - 18:53

score 39 · Answer 6 · 2026-03-11 15:36:34

39

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Working with divisors

Published on 11 Mar 2026 - 15:36

score 345 · Answer 7 · 2026-03-29 16:50:17

345

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A conjecture about prime numbers based on $\sigma_1(n)$ and the Highly Abundant Numbers

Published on 29 Mar 2026 - 16:50

score 135 · Answer 8 · 2026-03-27 15:36:11

135

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What inequalities similar Lagarias' statement are easy to prove?

Published on 27 Mar 2026 - 15:36

score 229 · Answer 9 · 2026-03-27 17:06:30

229

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An identity involving $[\sigma(n)]^2$

Published on 27 Mar 2026 - 17:06

score 40 · Answer 10 · 2016-01-12 22:58:32

40

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for which conditions of postive integer $n, m >0$ :$\dfrac{\sigma{(n)}}{n}\leq\dfrac{\sigma{(n+m)}}{n+m}$ hold?

Published on 12 Jan 2016 - 22:58

score 136 · Answer 11 · 2016-01-15 03:52:08

136

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Is $\lim\limits_{m\to\infty}\frac{1}{m}\sum_{n=1}^m \cos\left(\frac{2\pi nj}{s}\right)$ "useful"?

Published on 15 Jan 2016 - 3:52

score 122 · Answer 12 · 2016-01-18 23:03:45

122

Views

Inequality between two sums of numbers of divisors

Published on 18 Jan 2016 - 23:03

score 299 · Answer 13 · 2016-01-25 12:29:28

299

Views

A number $n$ has $12$ divisors and $d_{d_4-1} = (d_1+d_2+d_4)d_8$.

Published on 25 Jan 2016 - 12:29

score 128 · Answer 14 · 2016-01-26 18:27:01

128

Views

Any counter example for this claim?

Published on 26 Jan 2016 - 18:27

score 28 · Answer 15 · 2016-01-30 14:34:52

28

Views

How do i show this :$\lim_{k\to\infty} \frac{\sigma_{2k+1}(n)}{\sigma_{2k-1}(n)}=n²$ if it is true?

Published on 30 Jan 2016 - 14:34

List Question

Reference request: Do any papers on odd perfect numbers approach the problem using the following equation?

An integer is prime iff $\phi(n) \mid n-1$ and $n+1 \mid \sigma (n)$

Fourier transform for sum-of-divisors function

Fourier series concerning Gibbs constant and the divisor function.

What is an upper bound for $\frac{4x - \sigma(x)}{3x - \sigma(x)}$ when $x$ is deficient?

Working with divisors

A conjecture about prime numbers based on $\sigma_1(n)$ and the Highly Abundant Numbers

What inequalities similar Lagarias' statement are easy to prove?

An identity involving $[\sigma(n)]^2$

for which conditions of postive integer $n, m >0$ :$\dfrac{\sigma{(n)}}{n}\leq\dfrac{\sigma{(n+m)}}{n+m}$ hold?

Is $\lim\limits_{m\to\infty}\frac{1}{m}\sum_{n=1}^m \cos\left(\frac{2\pi nj}{s}\right)$ "useful"?

Inequality between two sums of numbers of divisors

A number $n$ has $12$ divisors and $d_{d_4-1} = (d_1+d_2+d_4)d_8$.

Any counter example for this claim?

How do i show this :$\lim_{k\to\infty} \frac{\sigma_{2k+1}(n)}{\sigma_{2k-1}(n)}=n²$ if it is true?

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