BinomialExpansion
  
  
    SpecialSequence
  
  
    IMO
  
  
    Challenging
  
  
  Let $\{a_n\}$ be a sequence defined as $a_n=\lfloor{n\sqrt{2}}\rfloor$ where $\lfloor{x}\rfloor$ indicates the largest integer not exceeding $x$. Show that this sequence has infinitely many square numbers.
 
    
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