KöMaL 2015 K484
Every natural number 1 to is written on a card. What is the smallest such that no matter how the cards are divided into two packs, there will always be two cards in one of the packs with two numbers that add up to a perfect square?
Official text KöMaL. Quoted with source.
Solutions
No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.
Similar problems
These problems have the most words in common with this statement.