The code in your post is only generating pairs, not rows. Also, each element in the List is only used in 1 pair.

That is correct. And also a 'pair' cannot appear in more than 1 Row.

Also, since you started with 36 elements in the array, and only 16 pairs were returned, there are still 4 elements in the array that werent assigned to pairs.

Well, I like to capture unique pairings. Since the elements doesn't follow a particular pattern we cannot decide the number of pairs for sure. Also 16 is my number and that may not be the maximum. Remaining pairs could be repeats of earlier pairs which I don't want.

Your logic could very well define the upper bound of the number of pairs however.

artist.