Seven is the sole number D for which the equation 2n − D = x2 has in excess of two solutions for n and x all-natural. Specifically, the equation 2n − 7 = x2 is recognized as the Ramanujan–Nagell equation. Not All people thinks that cats have 9 lives. In https://marcoieujy.loginblogin.com/45654190/7-day-pill-organizers-options