7 is the only real number D for which the equation 2n − D = x2 has in excess of two alternatives for n and x pure. Specifically, the equation 2n − 7 = x2 is named the Ramanujan–Nagell equation. Needless to say There exists also the effectively-recognised story of https://senioraidtools.com/auvon-imedassist-7-day-pill-organizer-review/