Tetrahedral Number

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 number


25

Random Words:

1. Ever Through Ashes ETA was created in the summer of 2004 striving for one purpose - to write and create invigorating yet original sounds..
1. When one man stands and spins his arm such as the blades of a helicopter while another bends over in front of him and makes a face of pu..
1. A female boner. The point which the women feels stimulated Mary experienced a Va-joner while making out with teddy. See boner, wet, va..