摘要: The sequence of triangle numbers is generated by adding the natural numbers. So the 7th triangle number would be 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28. The f... 阅读全文
posted @ 2015-02-05 18:42 liuwenjie 阅读(266) 评论(0) 推荐(0) 编辑