Seven is the one range D for which the equation 2n − D = x2 has much more than two solutions for n and x natural. In particular, the equation 2n − 7 = x2 is called the Ramanujan–Nagell equation. Jahannam has 7 gates which happen to be open up https://mobility-exercises-for-se06984.vidublog.com/36678623/the-greatest-guide-to-7-day-pill-organizers