Seven is the only real quantity D for which the equation 2n − D = x2 has a lot more than two alternatives for n and x all-natural. Specifically, the equation 2n − 7 = x2 is known as the Ramanujan–Nagell equation. The island of Ogygia was the home of https://mariohpkzn.blog-ezine.com/38056050/a-secret-weapon-for-7-day-pill-organizers