Time complexity of nested while with changing condition

I'm trying to solve the complexity of this loop

for(int i= 0; i < n; i++) {    
 c = i;    
 while(c > 1){     
  O(1);     
  c = c / 2;     
 }    
}

as the while condition changes in every loop I don't know how to calculate that strange series.

I mean, if the loop where

for(int i= 0; i < n; i++) {     
 c = n;     
 while(c > 1){     
  O(1);     
  c = c / 2;     
 }
}

I know the while has a complexity of O(logn) and it repeats itself n times, so the complexity would be O(nlogn).

The problem I have with previous loop is "c=i". As c=i, first time (c=0) the loop would reproduce 0 times, when c=1 it would reproduce 0 times again, when c=2 it would reproduce 1 time, then the series would follow and it is 0, 0, 1, 2, 2, 3, 3... (while reproductions each time of for loop)

O(logn) would not repeat itself n times, would repeat a number of times I can't come up with, so I don't know how to solve it.