阅读下面文言文，回答问题。

苏武牧羊

班  固

    律^①知武终不可胁，白单于。单于愈益欲降之，乃幽武，置大窖中，绝不饮食。天雨雪，武卧啮雪，与毡毛并咽之，数日不死。匈奴以为神，乃徒武北海上无人处，使牧羝，羝乳^②乃得归。

    武既至海上，廪食不至掘野鼠去^③草实而食之。杖汉节牧羊，卧起操持，节旄^④尽落。积五六年，单于弟於靬王弋射海上。武能网纺缴，檠^⑤弓弩，於靬王爱之，给其衣食。三岁余，王病，赐武马畜、服匿^⑥、穹庐。王死后，人众徙去。其冬，丁令^⑦盗武牛羊，武复穷厄。

    (选自《汉书》)

【注释】①律：卫律，投降匈奴，封为王。②羝(dī)乳：公羊产子。③去：藏。④旄：牦牛尾巴的毛。⑤檠(qǐng)：正弓的器具。⑥服匿(nì)：盛酒酪的器皿。⑦丁令：即丁灵、丁零。有说是指丁灵王卫律。

    Confidence is very important in daily life. It can help you to develop a healthy attitude （态度）.A study shows that the people who are more confident are much happier. They can have more chance to make themselves successful. But how to be more confident? Here are some suggestions:
    ·Speak loud   When you are not confident, you can't do well what you want to do. You speak in a voice so low that other people can hardly hear you. Try to speak loud enough so that people can hear you clearly. The .high voice can help you become more confident.
    ·Play sports   Physical exercise makes you tired but completely relaxed. 3 A strong body helps you be full of confidence.
    ·Encourage yourself   Write down a list of things you did during the day to see how many things you have done well. Did you finish your homework? Did you tell a joke that made everybody laugh? Give yourself praise for the good things you've done.
    ·Get rid of （消除） fear   Fear comes along with failure （失败）. But it's easy to overcome （克服） if you know that failure is part of your life. Don't hide your head just because you said something stupid last time. Try to start again and believe you can do better.
    ·Pick up a hobby    If you like singing, sing as much as you can. 4 In some ways, a hobby can make you outstanding. And it will make you happy and confident.

一个分数的分子是最小的奇质数，分母是最小的偶合数，这个分数就是____。

（Ⅰ）求 $\left\{a_n\right\}$ 的通项公式；

（Ⅱ）求 $e^{a_1}$ + $e^{a_2}$ +…+ $e^{a_n}$ .