Print-It-Yourself Puzzles

Currently Playing: Iwahswap (Hypex) - Is this the world's first truly hyper-exponential puzzle?

Print it yourself at https://oskarvandeventer.nl/Print-It-Yourself/. Buy at https://i.materialise.com/en/shop/item/iwahswap Iwahswap is the world's first truly hyper-exponential puzzle. That is, whenever the puzzle is expanded with one extra piece, the number of moves grows with a factor, and that factor increases with the number of pieces. The puzzle was developed in a creative exchange between Iwahiro (Hirokazu Iwasawa), Goetz Schwandtner, Bram Cohen and myself. The breakthrough idea came from Iwahiro, who suggested to look into the Steinhaus–Johnson–Trotter algorithm ( https://en.m.wikipedia.org/wiki/Steinhaus%E2%80%93Johnson%E2%80%93Trotter_algorithm ). That algorithm itself turned out to be too complex to implement mechanically, but Iwahiro found a simplification that was still hyper-exponential. Then I found a solution to implement it mechanically. The puzzle has five tiles that need to change order, from 12345 to 54321. The mechanism with the gray slider enforces that only neighboring tiles can be swapped (cf bubblesort). The dial above the tiles tells which tile can slide to the right, for swapping with a higher-numbered tile. The dial can be turned to a number if all numbers below are in order at one of the ends. Copyright (c) 2025, M. Oskar van Deventer. Frequently Asked Question: http://oskarvandeventer.nl/FAQ.html Buy mass-produced Oskar puzzles at https://www.puzzlemaster.ca/browse/inventors/oskar/ (USA, CA) and https://www.sloyd.fi/brain-teasers/inventors-designers/oskar-van-deventer (EU) Buy exclusive 3D-printed Oskar puzzles at https://i.materialise.com/shop/designer/oskarpuzzle, https://www.chewiescustompuzzles.com/puzzleshop/oskars-puzzles