7 is the sole selection D for which the equation 2n − D = x2 has over two methods for n and x all-natural. Particularly, the equation 2n − 7 = x2 is referred to as the Ramanujan–Nagell equation. As an early key selection from the number of constructive integers, https://johsocial.com/story2926688/an-unbiased-view-of-7zean