7 is the one range D for which the equation 2n − D = x2 has over two options for n and x normal. Especially, the equation 2n − seven = x2 is called the Ramanujan–Nagell equation. The island of Ogygia was the house of The gorgeous nymph named Calypso. https://jasperursfw.blogolize.com/getting-my-7-day-pill-organizers-to-work-76896632