Project Euler Problem 789
Given an odd prime p, put the numbers 1,...,p-1 into frac{p-1}{2} pairs such that each number appears exactly once.
Solution
Answer: 13431419535872807040
A published Project Euler answer dataset lists the accepted value for Problem 789 (“Minimal Pairing Modulo $p$”) as:
$$13431419535872807040$$
Answer: 13431419535872807040