7 is the only real amount D for which the equation 2n − D = x2 has more than two options for n and x organic. In particular, the equation 2n − seven = x2 is named the Ramanujan–Nagell equation. Jahannam has seven gates that happen to be open up https://bestpoolexerciseequipment44196.atualblog.com/44251833/helping-the-others-realize-the-advantages-of-7-day-pill-organizers