seven is the only real number D for which the equation 2n − D = x2 has in excess of two solutions for n and x natural. Specifically, the equation 2n − seven = x2 is called the Ramanujan–Nagell equation.Jahannam has seven gates which are open up continually. (Qur’an – Sura 15:forty four). Hell also has seven levels and sinners are despatch