ÉèµÈ±ÈÊýÁÐ{an}µÄÇ°nÏîºÍΪSn£¬ÒÑÖªan+1=2Sn+2(n¡ÊN*)£®
£¨1£©ÇóÊýÁÐ{an}µÄͨÏʽ£»
£¨2£©ÔÚanÓëan+1(n¡ÊN*)Ö®¼ä²åÈën¸ö1£¬¹¹³ÉÈçϵÄÐÂÊýÁУºa1£¬1£¬a2£¬1£¬1£¬a3£¬1£¬1£¬1£¬a4£¬¡£¬ÇóÕâ¸öÊýÁеÄÇ°2012ÏîµÄºÍ£»
£¨3£©ÔÚanÓëan+1Ö®¼ä²åÈën¸öÊý£¬Ê¹Õân+2¸öÊý×é³É¹«²îΪdnµÄµÈ²îÊýÁУ¨È磺ÔÚa1Óëa2Ö®¼ä²åÈë1¸öÊý¹¹³ÉµÚÒ»¸öµÈ²îÊýÁУ¬Æ乫²îΪd1£»ÔÚa2Óëa3Ö®¼ä²åÈë2¸öÊý¹¹³ÉµÚ¶þ¸öµÈ²îÊýÁУ¬Æ乫²îΪd2£¬¡ÒÔ´ËÀàÍÆ£©£¬ÉèµÚn¸öµÈ²îÊýÁеĺÍÊÇAn£®ÊÇ·ñ´æÔÚÒ»¸ö¹ØÓÚnµÄ¶àÏîʽg£¨n£©£¬Ê¹µÃAn=g£¨n£©dn¶ÔÈÎÒân¡ÊN*ºã³ÉÁ¢£¿Èô´æÔÚ£¬Çó³öÕâ¸ö¶àÏîʽ£»Èô²»´æÔÚ£¬Çë˵Ã÷ÀíÓÉ£®