Name: Tetrahedral Numbers: Sum of 'n' Consecutive Triangular Numbers: Proof
Uploaded: 2023-01-05T08:16:37+00:00
Duration: 26 min 13 s
Description: In this video I go over tetrahedral numbers and provide a proof of their formula using mathematical induction. This video was requested by Dominic from Strode College in the UK, and is a good follow-u

2 years ago

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In this video I go over tetrahedral numbers and provide a proof of their formula using mathematical induction. This video was requested by Dominic from Strode College in the UK, and is a good follow-up from my earlier video on the sum of consecutive integers.

A tetrahedral number is a number that can be visually represented as 3 sided pyramid, that is a tetrahedron. For example the numbers 1, 4, and 10 can all be visualized as a stack of balls in a tetrahedron pattern. In fact, the tetrahedron is just the sum of consecutive "triangular numbers", which are numbers that can be represented by an equilateral triangle.

I cover triangular or triangle numbers as well, and show that their formula is the sum of n consecutive integers. Finally, I use the triangle number formula as well as the principle of mathematical induction to prove the formula for a tetrahedron number. This was the first time I had learned about tetrahedron numbers so this was an interesting topic to cover. If you have any other video requests please let me know and I may cover it!

The topics covered as well as their timestamps are listed below.

- Introduction: 0:00
- Topics to Cover: 0:45
1. Shoutout to Dominic from Strode College: 1:22
2. Tetrahedral Numbers: 2:26
3. Triangular Numbers: 7:56
- Formula for a Triangular Number: 8:42
- Visualizing the Triangular Number Formula: 10:33
4. Formula for a Tetrahedral Number: 13:51
- Proof by Mathematical Induction: 17:37