
(a/(a-1))^a
|   10            |  2.86797199079241 | 
|   100          |  2.73199902642898 | 
|   1000        |  2.71964221644007 | 
|   10000      |    2.7184177550082 | 
|   100000    |      2.718295419741 | 
|   1000000  |  2.71828318761652 | 
