Meaning of tetrahedral number | Babel Free

Definitions

A number which results from the summation of consecutive triangular numbers, starting from 1. If the triangular numbers in such a summation are depicted as horizontal triangular arrays of units then these arrays can be stacked vertically to yield a tetrahedral array.

Examples

“The nᵗʰ tetrahedral number can be calculated with the formula #123;(n#43;1)³-(n#43;1)#92;over 6#125;.”

CEFR level