Monthly Archives: June 2012

I saw on yahoo today a 9X9 sudoku with only 21 numbers filled in. This sudoku was alleged to be the “most difficult sudoku ever.” I was thus motivated to write and post on yahoo the following, which I hope … Continue reading →

For those of you who came in “at the middle of the movie” and don’t want to go back and look for past posts for answers to your questions, the pistoncopter design is simply (for the simplest explanation) a single … Continue reading →