Seven is the only real amount D for which the equation 2n − D = x2 has greater than two solutions for n and x purely natural. Particularly, the equation 2n − seven = x2 is recognized as the Ramanujan–Nagell equation. 2 several hours back By Mashable Group A MacBook https://trentonkcvnr.wikicorrespondence.com/5633568/new_step_by_step_map_for_7_day_pill_organizers