Hello! Here is a really fun problem I came up with.
You are given a perfect square n.
Define a superpair in n as a 2(n−1)-tuple, (x1,x2,x3,...x2(n−1)), such that x1⋅x2⋯xn−1=xn⋅xn+1⋯x2(n−1), with 1≤xi≤n. In other words, all elements must be between 1 and n and the product of its first n−1 elements equals the product of its last n−1 elements.)
Find the set S of values of n that guarantee that it is possible to form list of n superpairs in n such that every number that appears in your superpair list appears exactly twice in your superpair list.
For example, we know that n=3 is in S because we can satisfy the conditions with the following superpair list:
(1,6,2,3)
(2,4,1,8)
(3,8,6,4)
Here, 1⋅6=2⋅3, 2⋅4=1⋅8, and 3⋅8=6⋅4. Additionally, every number present in the the superpair list, (1,2,3,4,6,8) appears exactly twice.
Notice that not all numbers from 1 to n need to be in your superpair list. Rather, you must only ensure that the ones that are in your superpair list, appear exactly twice. Hint: try using exactly n2−n distinct numbers in your superpair list.
I hope you enjoy!
"What is your solution to this problem? I'm curious."
"Hint: try using exactly n^2 -n distinct numbers in your superpair list.
How can you give us a hint if you do not know what the answer is ?
If you came up with it yourself and you do not know what the answer is then how can you claim it is 'beautiful'?