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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