Seven is the one number D for which the equation 2n − D = x2 has more than two alternatives for n and x normal. Particularly, the equation 2n − 7 = x2 is recognized as the Ramanujan–Nagell equation. 2 several hours ago By Mashable Crew A MacBook Professional for https://andyeiosd.vblogetin.com/43730730/not-known-details-about-7-day-pill-organizers