7 is the one selection D for which the equation 2n − D = x2 has in excess of two remedies for n and x pure. Specifically, the equation 2n − 7 = x2 is referred to as the Ramanujan–Nagell equation. two hours back By Mashable Team A MacBook pro https://cruzasfnv.ja-blog.com/38023440/everything-about-7-day-pill-organizers