Hi Marcel,
I wanted to know the index range used for the returned table od and so I tried to print before it starts and beyond the end, i.e. from -1 to 5.
The first output line shows #od witch I considered to be something like "size of". As you corrected, this gives the index of the last element.
The next line is od[-1] and there is no value so it prints "nil". I think you shouldn't worry about this.
The next output lines show the real content and above its last element "nil" again.
Gerald