Twitter announced their IPO via a tweet on 12th September 2013.
The popular Sudoku involves no mathematics at all. Instead of numbers, shapes, alphabet, colors, symbols etc. can be used. That's the beauty and simplicity of the puzzle! By the way, only 5,472,730,538 Sudoku are solvable. That's a big enough number in itself! Contrary to popular belief stemming probably from it's Japanese sounding name, Sudoku did not originate in Japan! It was created by an American Architect, Howard Garns, who called it Number Place - the Japanese still call it that. On a related note, the credit for popularising Sudoku goes to Wayne Gould, a Hong Kong judge. He spent several years in developing a computer program that would automatically generate these puzzles. Gould also convinced The Times in Britain to publish them. From there, Sudoku quickly reached US shores and spread around the world. [more...]