Definition:Ramanujan-Nagell Equation

Definition
The Ramanujan-Nagell equation is the Diophantine equation:
 * $x^2 + 7 = 2^n$

Also known as
The Ramanujan-Nagell equation is also known as Ramanujan's equation and Ramanujan's square equation.

Also see

 * Triangular Mersenne Numbers
 * Solutions of Ramanujan-Nagell Equation