Round Robin Cyclic Algorithm
Presume people are more used to number series starting with 1 instead of 0, and they want the first pair of the first round to be [1,2].
Then, functionally, the 1'st pair of the r'th round is:
[ 1 , (r+n-1-1) % (n-1) + 2 ], r=1..n-1
and the i'th pair of the r'th round is:
[ (r+i-2) % (n-1) + 2 , (r+n-i-1) % (n-1) + 2 ], r=1..n-1, i=2..n/2
Using these equations here is a version that outputs pairs
More stuff regarding round robins.