User Thomas Ahle

21 votes

3 answers

2k views

Efficient computation of $\sum_{k=1}^n \left\lfloor \frac{n}{k}\right\rfloor$

asked May 7, 2013 at 14:43

15 votes

1 answer

376 views

How did I solve this (triply logarithmic) equation?

asked Mar 11, 2019 at 10:34

14 votes

1 answer

424 views

Fastest curve from $p_0$ to $p_1$

asked Oct 23, 2013 at 10:28

10 votes

1 answer

824 views

Can a planar graph be drawn with all vertices on a straight line?

asked Dec 11, 2014 at 19:49

10 votes

2 answers

552 views

$E[|X-\mu|^n] \le 2 E[|X-\mu|^{n+1}]$ for Integer Random Variables

asked Apr 13, 2021 at 13:44

8 votes

2 answers

129 views

The expectation of $e^X \left(1-(1-e^{-X}\right)^n)$ when $X$ has Exponential Distribution

asked Feb 8, 2021 at 15:34

8 votes

1 answer

2k views

Difference between $R^\infty$ and $R^\omega$

asked Dec 23, 2013 at 16:53

8 votes

4 answers

1k views

Sum of kth roots ($\sum\sqrt[k]{m}$)

asked May 13, 2013 at 10:49

8 votes

2 answers

351 views

How to check if polylines can be untangled?

asked Jul 21, 2013 at 12:02

7 votes

1 answer

7k views

Sharper Lower Bounds for Binomial/Chernoff Tails

asked Nov 27, 2015 at 17:43

7 votes

2 answers

176 views

A Weighted Gaussian Inequality: $E[\frac{\sigma_n^2 x_n^2}{\sum_{i=1}^n \sigma_i^2x_i^2} ] \ge \frac{\sigma_n^2}{\sum_{i=1}^n \sigma_i^2}$

asked Oct 3, 2022 at 17:08

7 votes

2 answers

208 views

How can I improve my proof of Stirling's Theorem?

asked Jan 10 at 16:53

6 votes

2 answers

805 views

Is conditional entropy ever taken to be a random variable?

asked Jul 15, 2015 at 14:51

6 votes

5 answers

464 views

Does 'let x be a member of S...' require axiom of choice? [duplicate]

asked Jun 5, 2013 at 19:22

6 votes

4 answers

468 views

Entropy Lower Bound in Terms of $\ell_2$ norm

asked Dec 20, 2018 at 21:49

5 votes

1 answer

678 views

$\Pr[\sum_i X_i^2 Y_i^2\ge t]$, Chernoff bound for sum of pairs of squared Normal random variables

asked Dec 11, 2018 at 11:26

5 votes

1 answer

462 views

Tail Lower Bounds using Moment Generating Functions

asked Nov 16, 2020 at 14:45

5 votes

2 answers

3k views

Connection to Normal distribution

asked Apr 6, 2011 at 17:21

5 votes

1 answer

399 views

Power Mean Random Distribution

asked Apr 16, 2011 at 11:35

5 votes

2 answers

316 views

When can a metric space be embedded in the plane?

asked Dec 11, 2013 at 17:37

5 votes

2 answers

1k views

Asymptotic Moments of the Binomial Distribution, $E(X/(np))^k = 1 + O(k^2/n)$?

asked Jul 8, 2016 at 14:45

5 votes

0 answers

155 views

Geometric interpretation of $x_1^2y_1^2+x_2^2y_2^2+x_3^2y_3^2+\dots$

asked Dec 28, 2014 at 16:45

4 votes

1 answer

187 views

Are there any secure ciphers you can use without a computer?

asked Aug 7, 2012 at 15:42

4 votes

1 answer

160 views

Lower bound for $(x^c-1)^{1/c}$

asked Jun 9, 2014 at 22:08

4 votes

1 answer

93 views

Example of operation that is tree associative, but not generally associative

asked Jul 19, 2014 at 19:37

4 votes

0 answers

72 views

Expectation of $\frac{\langle Gx, Gy\rangle}{\|Gx\|_2\|G y\|_2}$ where $\langle x, y\rangle = \rho$

asked Jul 15, 2020 at 19:37

4 votes

0 answers

146 views

Examples of bijective polynomials $\mathbb C^n\to\mathbb C^n$ that aren't linear.

asked May 17, 2021 at 13:13

4 votes

0 answers

59 views

Matrix Recurence Relation, $M_n=M_{n-1}M_{n-2}$

asked Jul 29, 2021 at 3:13

4 votes

3 answers

219 views

Log (uniform) continuous functions

asked Mar 5, 2019 at 13:18

3 votes

2 answers

190 views

Distribution of $\sum_k \alpha^k X_k$

asked May 8, 2018 at 19:28

Stack Exchange Network

83 Questions

Efficient computation of $\sum_{k=1}^n \left\lfloor \frac{n}{k}\right\rfloor$

How did I solve this (triply logarithmic) equation?

Fastest curve from $p_0$ to $p_1$

Can a planar graph be drawn with all vertices on a straight line?

$E[|X-\mu|^n] \le 2 E[|X-\mu|^{n+1}]$ for Integer Random Variables

The expectation of $e^X \left(1-(1-e^{-X}\right)^n)$ when $X$ has Exponential Distribution

Difference between $R^\infty$ and $R^\omega$

Sum of kth roots ($\sum\sqrt[k]{m}$)

How to check if polylines can be untangled?

Sharper Lower Bounds for Binomial/Chernoff Tails

A Weighted Gaussian Inequality: $E[\frac{\sigma_n^2 x_n^2}{\sum_{i=1}^n \sigma_i^2x_i^2} ] \ge \frac{\sigma_n^2}{\sum_{i=1}^n \sigma_i^2}$

How can I improve my proof of Stirling's Theorem?

Is conditional entropy ever taken to be a random variable?

Does 'let x be a member of S...' require axiom of choice? [duplicate]

Entropy Lower Bound in Terms of $\ell_2$ norm

$\Pr[\sum_i X_i^2 Y_i^2\ge t]$, Chernoff bound for sum of pairs of squared Normal random variables

Tail Lower Bounds using Moment Generating Functions

Connection to Normal distribution

Power Mean Random Distribution

When can a metric space be embedded in the plane?

Asymptotic Moments of the Binomial Distribution, $E(X/(np))^k = 1 + O(k^2/n)$?

Geometric interpretation of $x_1^2y_1^2+x_2^2y_2^2+x_3^2y_3^2+\dots$

Are there any secure ciphers you can use without a computer?

Lower bound for $(x^c-1)^{1/c}$

Example of operation that is tree associative, but not generally associative

Expectation of $\frac{\langle Gx, Gy\rangle}{\|Gx\|_2\|G y\|_2}$ where $\langle x, y\rangle = \rho$

Examples of bijective polynomials $\mathbb C^n\to\mathbb C^n$ that aren't linear.

Matrix Recurence Relation, $M_n=M_{n-1}M_{n-2}$

Log (uniform) continuous functions

Distribution of $\sum_k \alpha^k X_k$