数列知识既是初等数学与高等数学的一个衔接点，又是历年高考考查的重点内容之一。在复习过程中，准确把握概念和公式，灵活运用公式变形去解题，往往会简化解题过程，提高解困速度，收到事半功倍的效果。设等基数列|an|的首项为a1，公差为d，通项为an，前n项和为s。（以下同） The series of knowledge is not only a connection point between elementary mathematics and advanced mathematics, but also one of the key contents of the college entrance examination. In the process of reviewing, accurately grasping the concepts and formulas, and flexibly applying formula distortions to solve problems, will often simplify the problem-solving process, increase the speed of resolving difficulties, and obtain a multiplier effect. Set the first item of the equal base series |an| to a1, the tolerance is d, the general term is an, and the first n items are s. (same below)