7 is the only range D for which the equation 2n − D = x2 has over two methods for n and x pure. Specifically, the equation 2n − 7 = x2 is named the Ramanujan–Nagell equation. Jahannam has seven gates which can be open all the time. (Qur’an – https://augustinek370mxk8.ouyawiki.com/user