Complexity Analysis of Nested Loops with Sigma Notation

Question

There are two nested for loops. I'm not sure but I think that it's geometric series, but I cannot get well solution for it. It seems n + n/2 + n/4 + .. + n/n^2, but how? What I tried is below up to now,

$$ \sum _{i=0}^{log\left(n-1\right)}\:\sum _{j=0}^{i-1}\:1 $$ $$ \sum _{i=0}^n\:\sum _{j=0}^n\:\left(\frac{1}{2}\right)^j $$

At first, I thought it's $O(nlogn)$ but instead as far as I research the right result is $O(n)$.

int try(int n) {   
    int sum = 0;   
    for (int i = n; i > 0; i /= 2) {     
        for (int j = 0; j < i; j++) {      
          sum += 1; 
          }
    }  
    return sum;
} 

Could you show its sigma notation with its complexity? I want to comprehend it with steps.