Counting Partitions of Sets and Bell Numbers | Combinatorics

preview_player
Показать описание
How many partitions are there of a set with n elements? We'll go over a few examples of counting partitions in today's lesson. We'll also discuss Bell numbers, Bell's triangle, and a recurrence relation for calculating Bell numbers.

I hope you find this video helpful, and be sure to ask any questions down in the comments!

+WRATH OF MATH+

Follow Wrath of Math on...

Рекомендации по теме
Комментарии
Автор

props to ur enthusiasm. If all teachers were as enthusiastic as you know knows maybe we would actually attend the lectures. Thx so much

djrkm
Автор

Great explanation thank you! I can also see the passion you have for the subject which is amazing, keep the great work.

tomascremaschi
Автор

Hey, this is my first time watching you, want you to know I loved this!! You are a good teacher.

LetsSink
Автор

I was introduced to this bell triangle as a way to count the number of possible equivalence relations on a set of n elements.... Back then I didn't know that every possible way to partition a set can be associated with an equivalence relation.

solitary
Автор

المُنقذ شكرًا جزيلًا.. I said in Arabic that you are Savior, so Thank you very much.

springvibes
Автор

Thank you it helped a lot i really like your way of teaching please keep it up i appreciate your work 😊

ftherogamer
Автор

Just osssm ❤️❤️❤️❤️loved it ..
Great explaination ..

Guys watch this, without any time waste...

pradeepmondal
Автор

Thanx it help me alot in public service exam for teaching.
❤️Love from INDIA 🇮🇳

vikasavasthi
Автор

Understood in just one go, thank you sir 😁

AnkitKumar-urgq
Автор

I was trying to find this by myself. But now I know I was wrong. Thank you very much for the video 😍

chamudisewmini
Автор

It was an amazing explanation, thank you so much!

mamaligakimchi
Автор

I have a question about these Bell numbers.

I was messing around with the infinite factorial sum for e. 1/n!
Then, I decided to see what would happen if I replaced 1 with n, so I wrote n/n!, and the answer was e.
Then, I squared the top n, and the answer I got was 2e.
Then, I cubed the n, and the answer I got was 5e.
I kept going with this, and I only got multiples of e: 2, 5, 15, 52, 203, 877, 4140...
Even with the first two sums I did, 1 is just n^0, and n is n^1, so I get the first two 1's of the sequence.

Why do these Bell numbers show up with e?

AManOfMusic
Автор

Amazing trick and teaching is very good attractive

naanungamulla
Автор

Please make full vedios and more for all combinatorics topics, thankyou!!😊

iitianrupa
Автор

I liked your video...it's very help for us sir...👌👌

avinashagrahari
Автор

Please provide a geometric and animated proof of WHY adding Stirling numbers of the second kind add up to Bell numbers. Also: please provide a non-recursive, closed formula for the Bell number and make a video that explains the formula in an intuitive way.

johndoe
Автор

10:14 I get confused on this part

for the last 2 elements why not add {3}, {4} but he then immediately jumps to 3 elements which is 1, 2, 3?

Edit: Okay nvm, he added it later on

ceerie
Автор

No entiendo si el numero de particiones de 3 es igual a 3 no 5

gatritioponsoutoni