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  ______    ______             _    _    _    _   
 /_   _//  /_   _//     ___   | || | || | |  | || 
 `-| |,-    -| ||-     /   || | || | || | |/\| || 
   | ||     _| ||_    | [] || | \\_/ || |  /\  || 
   |_||    /_____//    \__ ||  \____//  |_// \_|| 
   `-`'    `-----`      -|_||   `---`   `-`   `-` 
                         `-`

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發送短信 : On the sum of k-th powers of the first n positive integers