User RobPratt - Mathematics Stack Exchange

4 votes

How to get even numbers from adding pairs? (best title I thought of)

answered Aug 7, 2022 at 18:03

4 votes

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Minimizing distance of the mean from a point

answered Aug 7, 2022 at 1:10

4 votes

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How to prove $\sum_{k=1}^n (-1)^{(k+1)} k \binom nk=0$

answered Aug 31, 2022 at 23:09

4 votes

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Evaluating $\sum \limits_{k=1}^{\infty} \frac{\binom{4k}{2k}}{k^2 16^k}$

answered Apr 14, 2022 at 20:22

4 votes

How do I design the most unfair dice for this game?

answered Apr 17, 2022 at 1:23

4 votes

Combinatorial proof for $n\ge1$ of $3^n = \sum_{k=0}^n \binom{n}{k}(2^{n-k})$

answered Sep 21, 2021 at 21:27

4 votes

If $n$ is a natural number, then $4$ divides $5^n-1$.

answered Oct 13, 2021 at 3:58

4 votes

Minimum value of a maximum function

answered Sep 18, 2021 at 17:50

4 votes

How to prove the sum of squares degrees $d^2_{1}+d^2_{2}+\cdots+d^2_{95}\le 300000$ in a graph

answered Oct 31, 2021 at 21:38

4 votes

Accepted

Find the generating function of $f(n) = \sum_{k = 0}^n \binom{n}{k} (-1)^{n-k}C_{k}$

answered Dec 17, 2021 at 2:35

4 votes

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Mixed Integer Programming - variable that equals the sign of an expression

answered Dec 23, 2021 at 2:44

4 votes

Is it possible to place one queen and at least 29 knights in a 8x8 chess board such that no 2 pieces attack each other?

answered Aug 21, 2021 at 1:06

4 votes

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Find $\int_{-1}^{2}(5x^3+7x^2-9x+4)dx$ by Riemann sums

answered Feb 24, 2022 at 1:36

4 votes

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Find the sum (Includes binomial coefficients)

answered Jan 15, 2022 at 20:58

4 votes

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Count all the possible values of product of integers from $3$ sets

answered Dec 28, 2021 at 4:47

4 votes

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Find an optimal allocation of groups in an array

answered Dec 31, 2021 at 15:04

4 votes

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Integer partition generating functions problem

answered Mar 9, 2022 at 21:50

4 votes

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How many ways to choose 5 objects from 10 objects such that at least 3 objects are chosen from the first 5 objects?

answered Mar 10, 2022 at 20:06

4 votes

Can Adding a Convex Term to a Non-Convex Optimization Problem Make it Convex?

answered Mar 13, 2022 at 19:38

4 votes

is $\:\: x \not\in S \:\:$ same as $\:\:\neg (x \in S)\:\:$ same as $\:\:x \in {S}^\mathsf{c}$?

answered Mar 3, 2022 at 1:44

4 votes

Number of plates that can be placed on the table so that they neither overlap each other nor the edge of the table?

answered Feb 26, 2022 at 18:12

4 votes

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Approximating the absolute value function with a polynomial, starting from the Taylor series of $\sqrt{1-x}$

answered Mar 27, 2022 at 18:35

4 votes

Number of ways a committee could be formed if Mr $A$ refuses to serve on the committee if Ms $B$ is a member

answered Jan 2, 2020 at 14:22

4 votes

Accepted

How should I solve combination addition like this?

answered Jan 12, 2020 at 15:48

4 votes

Maximum number of students such that they all have at least 3 out of 6 different answers.

answered Jan 17, 2020 at 0:27

4 votes

Minimum number of dominoes on an $n \times n$ chessboard to prevent placement of another domino.

answered Jan 24, 2020 at 2:02

4 votes

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Intersections between two columns of equal number points

answered Aug 24, 2019 at 20:28

4 votes

Accepted

Construct $b_n$ so that $\sum_{n=0}^{\infty}b_n=B$

answered Aug 19, 2019 at 18:50

4 votes

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Guaranteed to guess two numbers in one from twelve lottery tickets, if falls $6$ balls with numbers from $1$ to $36$

answered Jun 29, 2019 at 14:07

4 votes

What is the pattern in this set {2, 3, 4, 6, 8, 9, 12, 16, 18, 24, ...}?

answered Sep 18, 2019 at 18:57

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1,968 Answers

How to get even numbers from adding pairs? (best title I thought of)

Minimizing distance of the mean from a point

How to prove $\sum_{k=1}^n (-1)^{(k+1)} k \binom nk=0$

Evaluating $\sum \limits_{k=1}^{\infty} \frac{\binom{4k}{2k}}{k^2 16^k}$

How do I design the most unfair dice for this game?

Combinatorial proof for $n\ge1$ of $3^n = \sum_{k=0}^n \binom{n}{k}(2^{n-k})$

If $n$ is a natural number, then $4$ divides $5^n-1$.

Minimum value of a maximum function

How to prove the sum of squares degrees $d^2_{1}+d^2_{2}+\cdots+d^2_{95}\le 300000$ in a graph

Find the generating function of $f(n) = \sum_{k = 0}^n \binom{n}{k} (-1)^{n-k}C_{k}$

Mixed Integer Programming - variable that equals the sign of an expression

Is it possible to place one queen and at least 29 knights in a 8x8 chess board such that no 2 pieces attack each other?

Find $\int_{-1}^{2}(5x^3+7x^2-9x+4)dx$ by Riemann sums

Find the sum (Includes binomial coefficients)

Count all the possible values of product of integers from $3$ sets

Find an optimal allocation of groups in an array

Integer partition generating functions problem

How many ways to choose 5 objects from 10 objects such that at least 3 objects are chosen from the first 5 objects?

Can Adding a Convex Term to a Non-Convex Optimization Problem Make it Convex?

is $\:\: x \not\in S \:\:$ same as $\:\:\neg (x \in S)\:\:$ same as $\:\:x \in {S}^\mathsf{c}$?

Number of plates that can be placed on the table so that they neither overlap each other nor the edge of the table?

Approximating the absolute value function with a polynomial, starting from the Taylor series of $\sqrt{1-x}$

Number of ways a committee could be formed if Mr $A$ refuses to serve on the committee if Ms $B$ is a member

How should I solve combination addition like this?

Maximum number of students such that they all have at least 3 out of 6 different answers.

Minimum number of dominoes on an $n \times n$ chessboard to prevent placement of another domino.

Intersections between two columns of equal number points

Construct $b_n$ so that $\sum_{n=0}^{\infty}b_n=B$

Guaranteed to guess two numbers in one from twelve lottery tickets, if falls $6$ balls with numbers from $1$ to $36$

What is the pattern in this set {2, 3, 4, 6, 8, 9, 12, 16, 18, 24, ...}?