Now this was pretty amazing! Simon’s new own code, that he so nonchalantly wrote while “having a break” from practicing recursive functions, generates “triangular numbers”.

A triangular number or triangle number counts the objects that can form an equilateral triangle. The *n*th triangular number is equal to the sum of the *n* natural numbers from 1 to *n*. The sequence of triangular numbers is

- 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 105, 120, 136, 153, 171, 190, 210, 231, 253, 276, 300, 325, 351, 378, 406 …

https://www.youtube.com/watch?v=Y2QaShP8vHY

“This particular piece of code works with any sequence”, Simon said:

He tried to build the whole triangle but got stuck.