Seven is the sole amount D for which the equation 2n − D = x2 has a lot more than two methods for n and x all-natural. Especially, the equation 2n − seven = x2 is named the Ramanujan–Nagell equation. Jahannam has seven gates which can be open continually. (Qur’an https://calebz342hjr8.wikibriefing.com/user