English Dictionary

tetrahedral number

名詞

(mathematics) 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.

日本語の意味

数学において、1から順に得られる連続する三角数の和により構成される数。三角数を水平な三角形状に配置し、それを積み重ねると四面体（テトラヘドロン）の形になることからこの名が付く。

When arranging cannonballs in a triangular pyramid, the total number in the stack is a tetrahedral number.

球を三角錐状に積み上げると、積み重ねた総数は四面体数になります。

意味（1）

(mathematics) 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.

The nᵗʰ tetrahedral number can be calculated with the formula (n+1)³-(n+1)/6.

tetrahedral numbers （ plural ）