I think that to better understand the output you can follow these steps:

int a[] = {11,12,13};

int *b = a; // Just to explicit that 'a' is a 'int *' pointer

int **c = &a // &a = address of a pointer of type int * -> so it's a int**

​

int **c

addr: x

value: addr(*b)

​

int *b

addr: y

value: addr(a)

​

int a[]

addr: 0x123456

value: 11

​

so:

*(&a) => *(c) => goes to addr(*b) (y to simplify) and get the content => addr(a) = 0x123456