I need to find the O-notation for the following bit of code:

```
for(i = 0; i < N; i++){
  for(j = 0; j < N; j+=i){
    x+=y;
  }
}

```

I've been able to get it down to O(N\*log(N)), but I want to be sure.  

Does this kind of function have a name I can look up and research?