What is Tetrahedral Number?
1.
The {n}th tetrahedral number is the sum of the first n Triangular numbers. Triangular numbers are the sum of the first n integers (1, 3, 6, 10, 15, etc.), and taking the sum of the triangular numbers results in the tetrahedral numbers (1, 4, 10, 20, 35, etc.)
The fifth tetrahedral number is the sum of the first five triangular numbers. The first five triangular numbers are 1, 3=1+2, 6=1+2+3, 10=1+2+3+4, and 15=1+2+3+4+5, so the sum of these numbers is 1+3+6+10+15= 35.
See
Random Words:
1.
A phrase used to describe an event where someone does something in completely the wrong fashion.
Oh Derek, you've made a complete ..
1.
Quite possibly, the greatest conman ever. See Scientology
Why Mister Tom Cruise, the evil aliens are attacking your brain. Give me the ..
