while(true) { Write it down; Think about it; Refine it; Sleep(); }
中文简要:
http://www.ruanyifeng.com/blog/2011/07/mathematical_constant_e.html
英文原文:
http://betterexplained.com/articles/an-intuitive-guide-to-exponential-functions-e/
其它参考:
http://zh.wikipedia.org/wiki/72%E6%B3%95%E5%89%87