you gotta be joking

Thanks for teaching me about this function!

I raised an issue.

Getting odds and evens swapped? Your list has 2,3,4,5,6 appearing odd number of times, the kata states there will be exactly one that appears an odd number of times. And yes, this trick only works if the input follows the rule.

I've tested this solution out, and if we give a list like [1, 1, 2, 3, 4, 5, 6], I get back 6. If I give it the list [1, 1, 2, 3, 4, 5], I get back 0.

Never knew ~, thanks bro

ref: Layz pattern match

refering to Wiki- Regular_paperfolding_sequence

Weird test cases after submitting

Falsifiable (after 1 test): 
expected: [2125,1955,173400,24]
 but got: [1,2,3,4]
24
85

Code in Haskell

fourPiles :: Int -> Int -> [Int]
fourPiles n y
  | n <= y = []
  | otherwise = [1,2,3,4]

Problem
According to the code I've submitted,

1. n = 24, y = 85, [] should be returned instead of [1,2,3,4]
2. sum of the exptected result[2125,1955,173400,24] is way more than n=24

You: No, you can't use it.
Me: Yes, I can.
LOL