Can anyone help me with this logic test?

I was given the following question in an interview, and I came up with the code below to compute the sum the code works and is correct, but I was told that this was a logic question and they weren't looking for the source code, can anyone shed a light on this? did they want me to write the pseudo code perhaps?

1. Compute the following sum:
   1/2 + 1/4 + 1/8 + ... + 1/1048576

   
   
   

   private static double computeSum()
    
    {
        double x = 0.0;
    
        for(double i=2; i<=1048576; i*=2)
        {
    
                x += (1 / i);
    
        }
    
        return x;         
    }
    

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