How this works: each tetrahedral number has 1+3+6+10 for beginners. For example, 20+15=35. 35 is a tetrahedral number. Let’s take a look at 120. 1+3+6+10+15++21+28+36=120. 120 is a tetrahedral number. Let’s look at 1. 1=1 1 is a tetrahedral number, even though there are not many blocks. Let’s look at 50. 1+3+6+10+15+21=56. 50 is not a tetrahedral number.
C2A Bugs: more favorites than views? How??
