7 is the only quantity D for which the equation 2n − D = x2 has greater than two methods for n and x natural. In particular, the equation 2n − 7 = x2 is called the Ramanujan–Nagell equation. One day a monk came by. They invited him to stay https://milobthui.blogdomago.com/36520230/not-known-factual-statements-about-7-day-pill-organizers