推 phxcon :才前一頁而已,請爬文 03/21 19:55
推 jaye1115 :第十項比等於"以第十項為等差中項的級數和" 03/21 22:15
→ jaye1115 :a10:b10=sa21:sb21 03/21 22:16
→ BRIANKUO :這種題目的數列真的存在嗎?有人試著找過嗎? 03/21 22:27
→ GameKnight :乘以 n 就有了 03/21 22:40
推 jaye1115 :sa19:sb19才對 03/21 23:24