Show HN: I made a little puzzle game about a rogue chess knight
(rakhim.org)
Reach the target to win.
Reach the target to win.
Mathematicians Find Proof to 122-Year-Old Triangle-to-Square Puzzle
(scientificamerican.com)
Mathematicians Find Proof to 122-Year-Old Triangle-to-Square Puzzle
Mathematicians Find Proof to 122-Year-Old Triangle-to-Square Puzzle
Rubik's Cube Solutions, Puzzles, and 8-Balls (2023)
(williambader.com)
My old racing Rubik's Cube http://www.rubiks.com is well-worn and barely holds together.
My old racing Rubik's Cube http://www.rubiks.com is well-worn and barely holds together.
Don't Think, Just Solve
(nytimes.com)
Max Park is a longtime speedcubing world record holder — for the 3x3x3 cube, his best official time is 3.13 seconds. Let's show you how he does it.
Max Park is a longtime speedcubing world record holder — for the 3x3x3 cube, his best official time is 3.13 seconds. Let's show you how he does it.
Stumbling Our Way into Solving the Oldest Board Game
(royalur.net)
The Royal Game of Ur, a 4500-year-old mystery, is now solved.
The Royal Game of Ur, a 4500-year-old mystery, is now solved.
A new Sudoku layout with 81 uniquely shaped cells
(danielchasehooper.com)
Something productive finally came from my daily Sudoku habit: I invented a new type of puzzle that I call “Cracked Sudoku”. It’s named after cracked dirt:
Something productive finally came from my daily Sudoku habit: I invented a new type of puzzle that I call “Cracked Sudoku”. It’s named after cracked dirt:
A Scientific American bolt puzzle
(leancrew.com)
A week or so ago, Scientific American republished this Martin Gardner puzzle from 1958:
A week or so ago, Scientific American republished this Martin Gardner puzzle from 1958:
Can you solve it? Clueless sudoku, a genius new puzzle
(theguardian.com)
Today I unveil a fantastic new type of Sudoku invented by reader Alf Smith. Like all Sudoku, the digits from 1 to 9 must appear in all rows, columns and boxes.
Today I unveil a fantastic new type of Sudoku invented by reader Alf Smith. Like all Sudoku, the digits from 1 to 9 must appear in all rows, columns and boxes.
Show HN: Betting game puzzle (Hamming neighbor sum in linear time)
(ycombinator.com)
In Spain, there's a betting game called La Quiniela: https://es.wikipedia.org/wiki/La_Quiniela_(Espa%C3%B1a)<p>Players predict the outcome of 14 football matches (home win, draw, away win). You win money if you get at least 10 correct, and the prize amount depends on the number of winners. Since all bets are public, the number of winners and the corresponding payouts can be estimated for each of the 3^14 possible outcomes.
In Spain, there's a betting game called La Quiniela: https://es.wikipedia.org/wiki/La_Quiniela_(Espa%C3%B1a)<p>Players predict the outcome of 14 football matches (home win, draw, away win). You win money if you get at least 10 correct, and the prize amount depends on the number of winners. Since all bets are public, the number of winners and the corresponding payouts can be estimated for each of the 3^14 possible outcomes.
Making any integer with four 2s
(thegreenplace.net)
There's a cute math puzzle that can be interesting to folks on very different levels:
There's a cute math puzzle that can be interesting to folks on very different levels:
Making any integer with four 2s
(thegreenplace.net)
There's a cute math puzzle that can be interesting to folks on very different levels:
There's a cute math puzzle that can be interesting to folks on very different levels:
A simple geometry question that fools almost everyone
(theguardian.com)
A triangle and a rectangle walked into a pub
A triangle and a rectangle walked into a pub
The largest sofa you can move around a corner
(quantamagazine.org)
A new proof reveals the answer to the decades-old “moving sofa” problem. It highlights how even the simplest optimization problems can have counterintuitive answers.
A new proof reveals the answer to the decades-old “moving sofa” problem. It highlights how even the simplest optimization problems can have counterintuitive answers.
Solving Sudoku with Tmux
(willhbr.net)
The question that everyone has been asking me since I compiled Python to run on tmux is: “can you actually do anything useful with this?”. I’m happy to report back that the answer is still no, but I can now use tmux to solve sudoku, and I can do it using a different and trickier approach than the one I used with the compiler.
The question that everyone has been asking me since I compiled Python to run on tmux is: “can you actually do anything useful with this?”. I’m happy to report back that the answer is still no, but I can now use tmux to solve sudoku, and I can do it using a different and trickier approach than the one I used with the compiler.
Explorable Flexagons: Learn to create and flex flexagons (2020)
(loki3.com)
Learn to create and flex flexagons
Learn to create and flex flexagons
From hours to 360ms: over-engineering a puzzle solution
(danielh.cc)
In January 2025, Jane Street posted an interesting puzzle:
In January 2025, Jane Street posted an interesting puzzle:
The Sudoku Affair
(explaining.software)
In 2006, Ron Jeffries wrote a series of posts describing his attempts to build a Sudoku solver.
In 2006, Ron Jeffries wrote a series of posts describing his attempts to build a Sudoku solver.
Embrace the Grind (2021)
(jacobian.org)
There’s this card trick I saw that I still think about all the time. It’s a simple presentation (which I’ve further simplified here for clarity): a volunteer chooses a card and seals the card in an envelope. Then, the magician invites the volunteer to choose some tea. There are dozens of boxes of tea, all sealed in plastic. The volunteer chooses one, rips the plastic, and chooses one of the sealed packets containing the tea bags.
There’s this card trick I saw that I still think about all the time. It’s a simple presentation (which I’ve further simplified here for clarity): a volunteer chooses a card and seals the card in an envelope. Then, the magician invites the volunteer to choose some tea. There are dozens of boxes of tea, all sealed in plastic. The volunteer chooses one, rips the plastic, and chooses one of the sealed packets containing the tea bags.
Cab Numbers
(shyamsundergupta.com)
Henry E. Dudeney [1] in his book "Amusements in Mathematics" mentions "The Cab Numbers" in the title of Problem No. 85.
Henry E. Dudeney [1] in his book "Amusements in Mathematics" mentions "The Cab Numbers" in the title of Problem No. 85.
A Puzzle about a Calculator
(aperiodical.com)
It’s now been a year since I took over the puzzle column at New Scientist and turned it into the BrainTwisters column. By way of celebration, I thought I’d write up an interesting bit of maths behind one of the puzzles, which I made a note of at the time and have been meaning to share.
It’s now been a year since I took over the puzzle column at New Scientist and turned it into the BrainTwisters column. By way of celebration, I thought I’d write up an interesting bit of maths behind one of the puzzles, which I made a note of at the time and have been meaning to share.
Build a working game of Tetris in Conway's Game of Life (2014)
(stackexchange.com)
Here is a theoretical question - one that doesn't afford an easy answer in any case, not even the trivial one.
Here is a theoretical question - one that doesn't afford an easy answer in any case, not even the trivial one.
Mathematician solves the moving sofa problem
(phys.org)
A mathematician at Yonsei University, in Korea, claims to have solved the moving sofa problem.
A mathematician at Yonsei University, in Korea, claims to have solved the moving sofa problem.
GCHQ Christmas Challenge Puzzles
(bbc.com)
Latin dancing, Indian butter and American soldiers are some of the clues for this year's cryptic Christmas challenge set by the national spy agency.
Latin dancing, Indian butter and American soldiers are some of the clues for this year's cryptic Christmas challenge set by the national spy agency.
Create your own jigsaw puzzle from any image
(puzzlezilla.com)
On this page, you can create a puzzle from any photo from the internet or your device. If you encounter difficulties, use the article on how to create your own puzzle
On this page, you can create a puzzle from any photo from the internet or your device. If you encounter difficulties, use the article on how to create your own puzzle