7 is the one number D for which the equation 2n − D = x2 has in excess of two methods for n and x normal. In particular, the equation 2n − seven = x2 is referred to as the Ramanujan–Nagell equation. The Jade Emperor right away questioned all the https://edgarvdjlk.theblogfairy.com/36854767/how-much-you-need-to-expect-you-ll-pay-for-a-good-7-day-pill-organizers