Summary: there are four kinds of triangle numbers with the tip up starting from 1. The sum of the most and the largest sum of the continuous natural numbers is the number of basic segments divided into each side of the triangle. The sum of each continuous natural number is less than the last one, until 1<br> <br>The number of triangle with the tip down is also the sum of the continuous natural number from 1. The first sum of the triangle is the second sum of the top point, and each sum is the largest two addends less than the previous one and so on until zero<br>
正在翻译中..