7 is the sole range D for which the equation 2n − D = x2 has a lot more than two solutions for n and x normal. Specifically, the equation 2n − seven = x2 is referred to as the Ramanujan–Nagell equation. The island of Ogygia was the house of https://senioraidtools.com/10-easy-mobility-exercises-for-seniors-to-stay-active-and-independent/