Solutions of Ramanujan-Nagell Equation/Mistake

Source Work

 * The Dictionary
 * $15$
 * $15$

Mistake

 * The equation $x^2 + 7 = 2^n$ has solutions for only $5$ values of $n$: $3, 4, 5, 7$ and $15$.

Correction
It needs to be pointed out that integer solutions only are under consideration here.

The equation in question is presented as a Diophantine equation.