@Absinthe
This was a lot of fun decided to do the problem by hand using non brute Force techniques. Attached are all the steps I used to solve the problem including the final solution on the last page.
Total number of coconuts is 3,121 at the start. The number of coconuts they ended up with was the following: 828, 703, 603, 523, 459
If your following the pages I attached the order in which you follow them is "knowns/reduce" then "All valid values" then "final solution"
@Absinthe They are readable here, should be good. Let me know if you have any questions on the math
@freemo the numbers are good, but I can't follow the screen grabs on my phone. Maybe more readable on the computer screen. Will see later.