数列 漸化式

                                                    &nbsp;<img itemprop="image" src="https://iwiz-chie.c.yimg.jp/im_sigg2EgKgOlMM_FhcTUG2hpw8g---exp5m-n1/d/iwiz-chie/note-170365-i1-_____.gif" alt="数列漸化式.gif">＊＊＊＊＊＊＊＊＊＊＊＊＊&nbsp;<img src="https://iwiz-chie.c.yimg.jp/im_sigg4ZnrMHmwiEK4_b.kfUvt7w---exp5m-n1/d/iwiz-chie/note-170365-i2-04-10-_5___.gif" alt="2013-04-10- 5　数列.gif">