Programming puzzles: processing lists!

[pdo]

Hello,

I don't know if this has been mentioned already for #37, and excuse me if I'm barging in and stating the obvious here, but I think there is a simple proof that the total number of match-day pairings for any even N is equal to (N-1)(N-3)(N-5)...1 and an efficient/elegant way of enumerating them would probably be recursive in nature.

Paul