A decagonal number is a figurate number that extends the concept of triangular and square numbers to the decagon (a ten-sided polygon). However, unlike the triangular and square numbers, the patterns involved in the construction of decagonal numbers are not rotationally symmetrical. Specifically, the nth decagonal numbers counts the number of dots in a pattern of n nested decagons, all sharing a common corner, where the ith decagon in the pattern has sides made of i dots spaced one unit apart from each other. The n-th decagonal number is given by the following formula The first few decagonal numbers are: 0, 1, 10, 27, 52, 85, 126, 175, 232, 297, 370, 451, 540, 637, 742, 855, 976, 1105, 1242, 1387, 1540, 1701, 1870, 2047, 2232, 2425, 2626, 2835, 3052, 3277, 3510, 3751, 4000, 4257, 4522, 4795, 5076, 5365, 5662, 5967, 6280, 6601, 6930, 7267, 7612, 7965, 8326 (sequence in the OEIS) The nth decagonal number can also be calculated by adding the square of n to thrice the (n−1)th pronic number or, to put it algebraically, as (Wikipedia).
Conversion Arcs and 2,916,485,648,612,232,232,816 (MegaFavNumbers)
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From playlist MegaFavNumbers
What are Irrational Numbers? | Number System | Don't Memorise
Watch this video to know more about Rational numbers, Irrational Numbers, Real Numbers and Number System. To learn more about Irrational Numbers, enroll in our full course now: https://infinitylearn.com/microcourses?utm_source=youtube&utm_medium=Soical&utm_campaign=DM&utm_content=CtRtXoT_
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Rational and Irrational Numbers
This math video tutorial provides a basic introduction into rational and irrational numbers. My Website: https://www.video-tutor.net Patreon Donations: https://www.patreon.com/MathScienceTutor Amazon Store: https://www.amazon.com/shop/theorganicchemistrytutor Subscribe: https://www.yo
From playlist GED Math Playlist
Irrational Numbers - What are they?
Learn what an irrational number is in this free math video tutorial by Mario's Math Tutoring. 0:07 What is an Irrational Number 0:11 What is an Integer 0:35 Example of a Rational Number 7 1:02 Example of How a Repeating Decimal is Rational 1:26 Example 1 is Square Root of 7 Rational? 1:40
From playlist Algebra 1
#MegaFavNumbers: 10,904,493,600 & Fibonacci Numbers
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Find The 10 Digit Number Classic Puzzle And Solution
I'm thinking of a 10 digit number that uses the each digit 0 to 9 exactly once and where the number formed by the first n digits is divisible by n. What could my number be? The video explains how to find the answer using tests for divisibility. Blog post: http://wp.me/p6aMk-4yS Divisibil
From playlist Logic Puzzles And Riddles
#MegaFavNumbers - 7,588,043,387,109,376 by Egi
87,109,376^2=7,588,043,387,109,376. The last 8 digits is the square root😀, it's called an automorphic number which n^2 ends with n
From playlist MegaFavNumbers
Use Proportions to Solve Applications (No Cross Products)
This video explains how to use ratios and rates to form proportions to solve applications problems
From playlist Number Sense - Decimals, Percents, and Ratios
Finding Interior and Exterior Angles in a Polygon
Learn how to find the Interior and Exterior Angles of a Polygon in this free math video tutorial by Mario's Math Tutoring. We discuss regular and nonregular polygons and go over the forumulas as well as example problems. 0:21 Formula for the Sum of Interior Angles in a Polygon 1:14 Formul
From playlist Geometry
NAMING POLYGONS | What is the name of 69 sided polygon?
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From playlist Summer of Math Exposition Youtube Videos
P. Apisa - Marked points in genus two and beyond
In the principal stratum in genus two, McMullen observed that something odd happens - there is only one nonarithmetic Teichmuller curve - the one generated by the decagon. This strange phenomenon begets another - a primitive translation surface in genus two admits a periodic point that is
From playlist Ecole d'été 2018 - Teichmüller dynamics, mapping class groups and applications
Interior and Exterior Angles of Polygons | Revision for Maths GCSE and IGCSE
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Think Thursday: Nine Digits [Algebra]
If this video is confusing, be sure to check out our blog for the full solution transcript! https://centerofmathematics.blogspot.com/2017/11/think-thursday-11-30-17-nine-digit.html
From playlist Center of Math: Think Thursday Problems
Find the Sum of the Angles of a Decagon
Find the Sum of the Angles of a Decagon If you enjoyed this video please consider liking, sharing, and subscribing. Udemy Courses Via My Website: https://mathsorcerer.com My FaceBook Page: https://www.facebook.com/themathsorcerer There are several ways that you can help support my chan
From playlist Polygons
Polygons & Quadrilaterals (Complete Geometry Course Lesson lesson 7)
This is the seventh lesson in Mario's Math Tutoring's Complete Geometry Course here on YouTube. We discuss formulas for finding the interior and exterior angles in polygons as well take a deep dive into quadrilaterals such as parallelograms, rhombi, rectangles, and squares as well as trap
From playlist Geometry Course (Complete Course - Mario's Math Tutoring)
J. Smillie - Horocycle dynamics (Part 2)
A major challenge in dynamics on moduli spaces is to understand the behavior of the horocycle flow. We will motivate this problem and discuss what is known and what is not known about it, focusing on the genus 2 case. Specific topics to be covered include: * SL_2(R) orbit closures and inva
From playlist Ecole d'été 2018 - Teichmüller dynamics, mapping class groups and applications
Junior Maths Challenge 2018 Questions 1,2,3,4 and 5 (UKMT)
'Get ready for A-level maths' course: https://mathsaurus.thinkific.com/courses/get-ready-for-a-level-maths This video includes questions from past UKMT maths challenge papers with the express permission of UK Mathematics Trust. The questions may not be copied or made available elsewhere
From playlist UKMT Junior Maths Challenge
ASVAB Practice Test 1 Mathematics Knowledge
In this video, I go through the ASVAB Practice Test 1 Mathematics Knowledge section. The concepts covered in this section include geometry, angles formed by intersecting lines, decimals, fractions, mixed numbers, improper fractions, percents, integers, exponents, converting units of measur
From playlist ASVAB Math Practice
Multiply Numbers By Drawing Lines
This is the higher quality version of how to multiply numbers by drawing lines. Get the Multiply By Lines Book! http://amzn.to/XRm7M4 If you like my videos, you can support me at Patreon: https://www.patreon.com/mindyourdecisions Connect on social media. I update each site when I have a
From playlist Mental Math Tricks