Consider an obtuse angled triangle ABC in which the difference between the largest and the smallest angle is $\frac{\pi}{2}$ and whose sides are in arithmetic progression. Suppose that the vertices of this triangle lie on a circle of radius 1. (There are two questions based on PARAGRAPH "I", the question given below is one of them)

Let $a$ be the area of the triangle $A B C$. Then the value of $(64 a)^2$ is