Permutations | Fixed points (mathematics) | Integer sequences
In combinatorial mathematics, a derangement is a permutation of the elements of a set, such that no element appears in its original position. In other words, a derangement is a permutation that has no fixed points. The number of derangements of a set of size n is known as the subfactorial of n or the n-th derangement number or n-th de Montmort number. Notations for subfactorials in common use include !n, Dn, dn, or n¡. For n > 0, the subfactorial !n equals the nearest integer to n!/e, where n! denotes the factorial of n and e is Euler's number. The problem of counting derangements was first considered by Pierre Raymond de Montmort in 1708; he solved it in 1713, as did Nicholas Bernoulli at about the same time. (Wikipedia).
The idea of ‘atonement’ sounds very old-fashioned and is deeply rooted in religious tradition. To atone means, in essence, to acknowledge one’s capacity for wrongness and one’s readiness for apology and desire for change. It’s a concept that every society needs at its center. For gifts and
From playlist RELATIONSHIPS
Why We May Be Angry Rather Than Sad
Behind many of our moods of depression lies something surprising: anger. Anger that hasn’t had the chance to know and express itself frequently curdles into depression – something we should bear in mind when trying to dig ourselves out of our saddest states of mind. If you like our films,
From playlist SELF
In this video, I define what it means to rearrange (or reshuffle) a series and show that if a series converges absolutely, then any rearrangement of the series converges to the same limit. Interesting Consequence: https://youtu.be/Mw7ocynGVmw Series Playlist: https://www.youtube.com/play
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Narcissism is the word we routinely use to describe someone self-satisfied and arrogant. But what do we really mean by the word – and are we applying it correctly? If you like our films, take a look at our shop (we ship worldwide): https://goo.gl/YfXSQO Join our mailing list: http://bit.ly
From playlist SELF
What is an enlargement dilation
👉 Learn about dilations. Dilation is the transformation of a shape by a scale factor to produce an image that is similar to the original shape but is different in size from the original shape. A dilation that creates a larger image is called an enlargement or a stretch while a dilation tha
From playlist Transformations
👉 Learn about dilations. Dilation is the transformation of a shape by a scale factor to produce an image that is similar to the original shape but is different in size from the original shape. A dilation that creates a larger image is called an enlargement or a stretch while a dilation tha
From playlist Transformations
👉 Learn about dilations. Dilation is the transformation of a shape by a scale factor to produce an image that is similar to the original shape but is different in size from the original shape. A dilation that creates a larger image is called an enlargement or a stretch while a dilation tha
From playlist Transformations
Here is a demonstration of the doppler effect.
From playlist All Demonstrations
Generating digraphs with derangements by Daniel Horsley
CMSA Combinatorics Seminar, 15 July 2020
From playlist CMSA Combinatorics Seminar
Why Secret Santa usually fails – a combinatorial quest
This is an entry to #SoME2. While providing some historical and mathematical context (and a few nice examples) along the way, it works towards a closed-form solution of the problem of finding the probability that a randomly chosen permutation of a given number of objects is a derangement,
From playlist Summer of Math Exposition 2 videos
Being a victim of infidelity is one of the worst things that can befall us in love. One of the ways to come back from the harrowing experience is to ask what the real meaning of the infidelity might be. If you like our films, take a look at our shop (we ship worldwide): https://goo.gl/yW1
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Derangements featuring Dr James Grime. More links & stuff in full description below ↓↓↓ Extra footage from this interview: https://youtu.be/qYAWjIVY7Zw More Dr Grime on Numberphile: http://bit.ly/grimevideos e video: https://youtu.be/AuA2EAgAegE Special thanks to these Patrons on Patreo
From playlist James Grime on Numberphile
This video introduces the topic of derangements of elements. mathispower4u.com
From playlist Counting (Discrete Math)
Due to the COVID-19 pandemic, Carnegie Mellon University is protecting the health and safety of its community by holding all large classes online. People from outside Carnegie Mellon University are welcome to tune in to see how the class is taught, but unfortunately Prof. Loh will not be o
From playlist CMU 21-228 Discrete Mathematics
Holiday Special: Secret Santa and Derangements
Jacob mathematically investigates the task of setting up a "Secret Santa" gift exchange.
From playlist Center of Math BLOG: Holiday Mathematics
Find the Number of Permutations with One Fixed Element Using Derangements
This video explains how to determine the number of permutations that have 1 fixed element. mathispower4u.com
From playlist Counting (Discrete Math)
Lecture 18 - Probability G. F.
This is Lecture 18 of the CSE547 (Discrete Mathematics) taught by Professor Steven Skiena [http://www.cs.sunysb.edu/~skiena/] at Stony Brook University in 1999. The lecture slides are available at: http://www.cs.sunysb.edu/~algorith/math-video/slides/Lecture%2018.pdf More information may
From playlist CSE547 - Discrete Mathematics - 1999 SBU
[Discrete Mathematics] Derangements
We talk about derangements. Visit our website: http://bit.ly/1zBPlvm Subscribe on YouTube: http://bit.ly/1vWiRxW *--Playlists--* Discrete Mathematics 1: https://www.youtube.com/playlist?list=PLDDGPdw7e6Ag1EIznZ-m-qXu4XX3A0cIz Discrete Mathematics 2: https://www.youtube.com/playlist?list=
From playlist Discrete Math 2
Which Incapacitating Agent is the Most Effective?
This time, we're ranking incapacitating agents! The term incapacitating agent is defined by the United States Department of Defense as: "An agent that produces temporary physiological or mental effects, or both, which will render individuals incapable of concerted effort in the performance
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Discrete Math II - 8.6.4 Apply the Principle of Inclusion Exclusion: Derangements
We started section 8.6 by looking at how to determine the number of ways all conditions aren't met. In this video, we look at finding an approximation of that number based on the irrational number, e. Video Chapters: Intro 0:00 Brute Force Derangement 0:11 Derangement Example (n=3) 1:44
From playlist Discrete Math II/Combinatorics (entire course)