> I've read about this story in Graham Farmelo's book The Strangest Man: The Hidden Life of Paul Dirac, Quantum Genius. "The Strangest Man": https://en.wikiped

> I've read about this story in Graham Farmelo's book The Strangest Man: The Hidden Life of Paul Dirac, Quantum Genius. "The Strangest Man": https://en.wikipedia.org/wiki/The_Strangest_Man https://en.wikipedia.org/wiki/The_Strangest_Man Four Fours: https://en.wikipedia.org/wiki/Four_fours https://en.wikipedia.org/wiki/Four_fours : > Four fours is a mathematical puzzle, the goal of which is to find the simplest mathematical expression for every whole number from 0 to some maximum, using only common mathematical symbols and the digit four. No other digit is allowed. Most versions of the puzzle require that each expression have exactly four fours, but some variations require that each expression have some minimum number of fours.